Taking of Marine Mammals Incidental to Specific Activities; Taking of Marine Mammals Incidental to Pile Driving and Removal Activities During Construction of a Cruise Ship Berth, Hoonah, Alaska, 18495-18521 [2019-08848]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 84 (Wednesday, May 1, 2019)]
[Notices]
[Pages 18495-18521]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-08848]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG874


Taking of Marine Mammals Incidental to Specific Activities; 
Taking of Marine Mammals Incidental to Pile Driving and Removal 
Activities During Construction of a Cruise Ship Berth, Hoonah, Alaska

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request Duck Point Development II, LLC. 
(DPD) for authorization to take marine mammals incidental pile driving 
and removal activities during construction of a second cruise ship 
berth and new lightering float at Cannery Point (Icy Strait) on 
Chichagof Island near Hoonah, Alaska. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an incidental harassment authorization (IHA) to incidentally take 
marine mammals during the specified activities. NMFS is also requesting 
comments on a possible one-year renewal that could be issued under 
certain circumstances and if all requirements are met, as described in 
Request for Public Comments at the end of this notice. NMFS will 
consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorizations and agency responses will 
be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than May 31, 
2019.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act without change. All personal identifying 
information (e.g., name, address) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

FOR FURTHER INFORMATION CONTACT: Stephanie Egger, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment. This action is consistent with categories of 
activities identified in Categorical Exclusion B4 (incidental 
harassment authorizations with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed IHA 
qualifies to be categorically excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On December 28, 2018 NMFS received a request DPD for an IHA to take 
marine mammals incidental to pile driving and removal activities during 
construction of a second cruise ship berth and new lightering float at 
Cannery Point (Icy Strait) on Chichagof Island near Hoonah, Alaska. The 
application was deemed adequate and complete on April 3, 2019. The 
applicant's request is for take nine species of marine mammals by Level 
B harassment and three species by Level A harassment. Neither DPD nor 
NMFS

[[Page 18496]]

expects serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate. NMFS previously issued an IHA to the 
Huna Totem Corporation for the first cruise ship berth in Hoonah, AK in 
2015 (80 FR 31352; June 2, 2015).

Description of Proposed Activity

Overview

    The purpose of this project is to construct a second offshore 
mooring facility and small-craft lightering float to accommodate the 
exponential growth in cruise ship traffic Hoonah is currently 
experiencing. The project is needed because the existing berth 
configuration does not have the capacity to support multiple cruise 
ships at the same time. Furthermore, the increase in small vessel 
traffic generated by the increase in visitor numbers necessitates the 
addition of a small-boat lightering float for short excursions around 
Icy Strait Point. Once the project is constructed, Hoonah will be 
better able to accommodate the increased number of cruise ships and 
passengers visiting the community. Therefore, Duck Point Development 
proposes to construct a second cruise ship berth and new lightering 
float at Cannery Point (Icy Strait) on Chichagof Island near Hoonah, 
Alaska, in order to accommodate the increase in cruise ship and visitor 
traffic since completion of the first permanent cruise ship berth 
completion in 2016 (80 FR 31352; June 2, 2015). The in-water sound from 
the pile driving and removal activities, may incidentally take nine 
species of marine mammals by Level B harassment and three species by 
Level A harassment.
    Revenue generated from the tourism industry is a vital part of 
Hoonah's economy. Since the addition the permanent cruise ship berth in 
2016, Hoonah has become a top cruise ship port in Alaska, with growth 
from 34 ship visits in 2004 to a projected 122 visits in 2019 (Alaska 
Business Monthly 2018). Prior to placement of the permanent berth, 
cruise ship passengers were transferred to shore via smaller, 
``lightering'' vessels. Construction of the berth allowed for direct 
walking access from ships to the shore, and more passengers 
disembarking in Hoonah. In 2016, an estimated 150,000 passengers 
visited Hoonah on 78 large-scale cruise ships, with many visiting 
Hoonah's shops and restaurants (LeMay Engineering & Consulting 2018).
    The existing berth can only accommodate one large vessel at a time. 
Oftentimes a second visiting ship is forced to idle in Port Frederick 
Inlet near the cannery to wait for mooring space, or return to the 
traditional methods of lightering passengers to shore via small 
vessels. In addition to safety concerns stemming from decreased large-
ship maneuverability at this location, idling ships and lightering 
vessels increase fuel consumption, noise, and hydrocarbon pollution 
within the inlet. A second shore berth is needed to allow multiple 
cruise ships' pedestrian visitors access directly to shore.
    The increase in visitors to Hoonah has concurrently increased 
demand for offshore day excursions around Port Frederick and Icy Strait 
for wildlife viewing. An additional lightering float on the west side 
of the point, nearer to the Icy Strait Cannery, is needed to add 
mooring capacity for small vessels providing these short-day 
excursions.

Dates and Duration

    The applicant is requesting an IHA to conduct pile driving and 
removal over 75 working days (not necessarily consecutive) beginning 
June 1, 2019 and extending into November 2019 as needed. Approximately 
39 days of vibratory and 8 days of impact hammering will occur. An 
additional 14 days of socketing and 14 days of anchoring will occur to 
stabilize the piles. These are discussed in further detail below.

Specific Geographic Region

    The proposed project is located off Cannery Point, approximately 
2.4 kilometers (km) north of Hoonah in Southeast Alaska; T43S, R61E, 
S20, Copper River Meridian, USGS Quadrangle Juneau A5 NE; latitude 
58.1351 and longitude -135.4506 (see Figure 1 of the application). The 
project is located at the confluence of Icy Strait and Port Frederick 
Inlet. The proposed cruise ship berth would be installed approximately 
0.5 kilometer (km) (0.3 miles) east of the existing permanent cruise 
ship berth in Icy Strait. A separate small craft lightering float would 
be installed between two existing docks in Port Frederick Inlet on the 
west side of Cannery Point (alternatively called Icy Strait Point; see 
Figure 1 below and Figure 4 of the application).

[[Page 18497]]

[GRAPHIC] [TIFF OMITTED] TN01MY19.003

    Icy Strait is part of Alaska's Inside Passage, a route for ships 
through Southeast Alaska's network of islands, located between 
Chichagof Island and the North American mainland. Port Frederick is a 
24-km inlet that dips into northeast Chichagof Island from Icy Strait, 
leading to Neka Bay and Salt Lake Bay. The inlet varies between 4 and 
almost 6 km wide with a depth of up to 150 meters (m). The inlet near 
the proposed project is 14 to 35 m deep (Figure 9, NOAA 2016). NMFS's 
ShoreZone Mapper details the proposed project site as a semi-protected/
partially mobile/sediment or rock and sediment habitat class with 
gravel beaches environmental sensitivity index (NMFS 2018c).

Detailed Description of Specific Activity

    To construct a new cruise ship berth (Berth II), lightering float, 
associated support structures, and pedestrian walkway connections to 
shore, the project would require the following:
    [ssquf] Installation of 62 temporary 30-inch (in) diameter steel 
piles as templates to guide proper installation of permanent piles 
(these piles would be removed prior to project completion);
    [ssquf] Installation of 8 permanent 42-in diameter steel piles, 16 
permanent 36-in diameter steel piles, and 18 permanent 24-in diameter 
steel piles to support a new 500 feet (ft) x 50 ft floating pontoon 
dock, its attached 400 ft x 12 ft small craft float, mooring 
structures, and shore-access fixed-pier walkway (Figure 6 of the 
application)
    [ssquf] Installation of three permanent 30-in diameter steel piles 
to support a 120 ft x 20 ft lightering float, and four permanent 16-in 
diameter steel piles above the high tide line to construct a 12 ft x 40 
ft fixed pier for lightering float shore access (Figure 7 of the 
application);
    [ssquf] Installation of bull rail, floating fenders, mooring 
cleats, and mast lights. (Note: These components would be installed out 
of the water.)
    [ssquf] Socketing and rock anchoring to stabilize the piles.
Construction Sequence
    In-water construction of Berth II would begin with installation of 
an approximately 300-ft-long fixed pier. Temporary 30-in piles would be 
driven into the bedrock by a vibratory hammer to create a template to 
guide installation of the permanent piles. A frame would be welded 
around the temporary piles. Permanent 36-in and 42-in piles would then 
be driven into the bedrock using vibratory and impact pile driving.
    Installation of the lightering float and fixed pier would begin 
with removal of a single existing wood pile separate from the existing 
wooden pier by direct-pull methods using a crane. Three 30-in steel 
piles would then be driven in using a vibratory hammer in to support 
the new lightering float structure. Additionally, (4) 16-in steel piles 
would be installed with a vibratory hammer (on land) for the lightering 
float's fixed pier and placement of a gangway to connect the two 
components. The 16-in steel piles are not discussed further because 
they occur on land and are not expected to impact species under water.
Installation and Removal of Temporary (Template) Piles
    Temporary 30-in steel piles would be installed and removed using a 
vibratory hammer (Table 1). If needed for stability, the contractor 
would socket in up to 10 of these piles if a sufficient quantity of 
overburden is not present (Table 1). Socketing is also known as down-
the-hole drilling or downhole drilling (DTH drilling) to secure a pile 
to the bedrock. During socketing, the DTH hammer and under-reamer bit 
drill a hole into the bedrock and then socket

[[Page 18498]]

the pile into the bedrock. We refer to it as socketing throughout this 
document to clarify this method from rock anchoring, which also uses a 
drill.
Installation of Permanent Piles
    Eighteen permanent 24-in steel piles would be installed through 
sand and gravel with a vibratory hammer (Table 1). All of the 18 
permanent 24in steel piles will be secured into underlying bedrock with 
socketing (Table 1). Socket depths are expected to be approximately 
five ft (as determined by the geotechnical engineer). Two of the 24-in 
steel piles may also be secured through rock anchoring (Table 1). Rock 
anchoring is the method of drilling a shaft into the concrete, inside 
of the existing pile, and filling it with concrete to stabilize the 
pile. After a pile is impacted, the pile would be anchored using an 8in 
diameter drilled shaft within the pile. Once the shaft is drilled, a 
DTH hammer with an 8in diameter bit will be used to drill a shaft 
(depth as determined by geotechnical engineer) into the bedrock and 
filled with concrete to install the rock anchors.
    Sixteen permanent 36-in steel piles and 8 permanent 42-in steel 
piles would be driven through sand and gravel with a vibratory hammer 
and impacted into bedrock (Table 1). After being impacted, all 24 of 
these piles would be anchored using a smaller 33-in diameter drilled 
shaft within the pile (Table 1). Once the shaft is drilled, a DTH 
hammer with a 33-in diameter bit (isolated from the steel casing) will 
be used to drill a shaft (depth as determined by geotechnical engineer) 
into the bedrock and filled with concrete to install the rock anchors. 
During this anchor drilling, the larger diameter piles would not be 
touched by the drill; therefore, anchoring will not generate steel-on-
steel hammering noise (noise that is generated during socketing).
    In addition, 3 permanent 30-in steel piles would be driven through 
sand and gravel with a vibratory hammer only to support the lightering 
float (Table 1).

                           Table 1--Pile Driving and Removal Activities Required for the Hoonah Berth II and Lightering Float
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                                                                                                 Project Component
                                                         -----------------------------------------------------------------------------------------------
                       Description                        Temporary pile  Temporary pile  Permanent pile  Permanent pile  Permanent pile  Permanent pile
                                                           installation       removal      installation    installation    installation    installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Diameter of Steel Pile (inches).........................              30              30              24              30              36              42
# of Piles..............................................              62              62              18               3              16               8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Quantity..........................................              62              62              18               3              16               8
Max # Piles Vibrated per Day............................               6               6               4               2               2               2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Quantity..........................................               0               0               0               0              16               8
Max # Piles Impacted per Day............................               0               0               0               0               4               2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Socketed Pile Installation (Down-Hole Drilling)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Quantity..........................................              10               0              18               0               0               0
Max # Piles Socketed per Day............................               2               0               2               0               0               0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Rock Anchor Installation (Drilled Shaft)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Quantity..........................................               0               0               2               0              16               8
Diameter of Anchor......................................  ..............  ..............               8               0              33              33
Max # Piles Anchored per Day............................               0               0               1               0               2               2
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In addition to the activities described above, the proposed action 
will involve other in-water construction and heavy machinery 
activities. Other types of in-water work including with heavy machinery 
will occur using standard barges, tug boats, barge-mounted excavators, 
or clamshell equipment to place or remove material; and positioning 
piles on the substrate via a crane (i.e., ``stabbing the pile''). 
Workers will be transported from shore to the barge work platform by a 
25-ft skiff with a 125-250 horsepower motor in the morning and at the 
end of the work day. The travel distance will be less than 300 ft. 
There could be multiple (up to eight) shore-to-barge trips during the 
day; however, the area of travel will be relatively small and close to 
shore. We do not expect any of these other in-water construction and 
heavy machinery activities to take marine mammals as these activities 
occur close to the shoreline (less than 300 feet), but as additional 
mitigation, DPD is proposing a 10 m shutdown zone for these additional 
in-water activities. Therefore, these other in-water construction and 
heavy machinery activities will not be discussed further.
    For further details on the proposed action and project components, 
please refer to Section 1.2.4. and 1.2.5 of the application.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).

[[Page 18499]]

    Table 2 lists all species with expected potential for occurrence in 
the project area and summarizes information related to the population 
or stock, including regulatory status under the MMPA and ESA and 
potential biological removal (PBR), where known. For taxonomy, we 
follow Committee on Taxonomy (2016). PBR is defined by the MMPA as the 
maximum number of animals, not including natural mortalities, that may 
be removed from a marine mammal stock while allowing that stock to 
reach or maintain its optimum sustainable population (as described in 
NMFS's SARs). While no mortality is anticipated or authorized here, PBR 
and annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Pacific and Alaska SARs (Carretta et al., 2018; Muto et 
al., 2018). All values presented in Table 2 are the most recent 
available at the time of publication (draft SARS available online at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                                 Table 2--Marine Mammals Occurrence in the Project Area
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                                                                                        ESA/ MMPA
                                                                                         status;       Stock abundance (CV,                    Annual M/
            Common name                  Scientific name             Stock           strategic (Y/N)    Nmin, most recent           PBR          SI \3\
                                                                                           \1\        abundance survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray Whale.....................  Eschrichtius robustus.  Eastern N Pacific....  -, -, N           26,960 (0.05, 25,849,  801.............        138
                                                                                                       2016).
Family Balaenopteridae (rorquals):
    Minke Whale....................  Balaenoptera            Alaska...............  -, -, N           N/A (see SAR, N/A,     UND.............          0
                                      acutorostrata.                                                   see SAR).
    Humpback Whale.................  Megaptera novaeangliae  Central N Pacific      -, -, Y           10,103 (0.3, 7,890,    83..............         25
                                                              (Hawaii and Mexico                       2006) (Hawaii DPS
                                                              DPS).                                    9,487 \a\ Mexico DPS
                                                                                                       606 \ a\).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
    Sperm whale....................  Physeter macrocephalus  North Pacific........  E, D, Y           N/A (see SAR, N/A,     See SAR.........        4.4
                                                                                                       2015).
Family Delphinidae:
    Killer Whale...................  Orcinus orca..........  Alaska Resident......  -, -, N           2,347 c (N/A, 2347,    24..............          1
                                                                                                       2012).
                                                             Northern Resident....  -, -, N           261 c (N/A, 261,       1.96............          0
                                                                                                       2011).
                                                             West Coast Transient.  -, -, N           243 c (N/A, 243,       2.4.............          0
                                                                                                       2009).
    Pacific White-Sided Dolphin....  Lagenorhynchus          N Pacific............  -, -, N           26,880 (N/A, N/A,      UND.............          0
                                      obliquidens.                                                     1990).
Family Phocoenidae (porpoises):
    Dall's Porpoise................  Phocoenoides dalli....  AK...................  -, -, N           83,400 (0.097, N/A,    UND.............         38
                                                                                                       1991).
    Harbor Porpoise................  Phocoena phocoena.....  Southeast Alaska.....  -, -, Y           see SAR (see SAR, see  8.9.............         34
                                                                                                       SAR, 2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller Sea Lion...............  Eumetopias jubatus....  Western DPS..........  E, D, Y           54,267 a (see SAR,     326.............        252
                                                                                                       54,267, 2017).
                                                             Eastern DPS..........  T, D, Y           41,638 a (see SAR,     2498............        108
                                                                                                       41,638, 2015).
Family Phocidae (earless seals):
    Harbor Seal....................  Phoca vitulina........  Glacier Bay/Icy        -, -, N           7,210 (see SAR,        169.............        104
                                                              Strait.                                  5,647, 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable [explain if this is the case].
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
Note--Italicized species are not expected to be taken or proposed for authorization.
\a\ Under the MMPA humpback whales are considered a single stock (Central North Pacific); however, we have divided them here to account for distinct
  population segments (DPSs) listed under the ESA. Using the stock assessment from Muto et al. 2018 for the Central North Pacific stock (10,103) and
  calculations in Wade et al. 2016, 93.9% of the humpback whales in Southeast Alaska are expected to be from the Hawaii DPS and 6.1% are expected to be
  from the Mexico DPS.

    All species that could potentially occur in the proposed survey 
areas are included in Table 2. In addition, the Northern sea otter 
(Enhydra lutris kenyoni) may be found in the project area. However, sea 
otters are managed by the U.S. Fish and Wildlife Service and are not 
considered further in this document.

[[Page 18500]]

Minke Whale

    In the North Pacific Ocean, minke whales occur from the Bering and 
Chukchi seas south to near the Equator (Leatherwood et al., 1982). In 
the northern part of their range, minke whales are believed to be 
migratory, whereas, they appear to establish home ranges in the inland 
waters of Washington and along central California (Dorsey et al. 1990). 
Minke whales are observed in Alaska's nearshore waters during the 
summer months (National Park Service (NPS) 2018). Minke whales are 
usually sighted individually or in small groups of 2-3, but there are 
reports of loose aggregations of hundreds of animals (NMFS 2018d). 
Minke whales are rare in the action area, but they could be 
encountered. During the construction of the first Icy Strait cruise 
ship berth, a single minke was observed during the 135-day monitoring 
period (June 2015 through January 2016) (BergerABAM 2016).
    No abundance estimates have been made for the number of minke 
whales in the entire North Pacific. However, some information is 
available on the numbers of minke whales in some areas of Alaska. Line-
transect surveys were conducted in shelf and nearshore waters (within 
30-45 nautical miles of land) in 2001-2003 from the Kenai Fjords in the 
Gulf of Alaska to the central Aleutian Islands. Minke whale abundance 
was estimated to be 1,233 (CV = 0.34) for this area (Zerbini et al., 
2006). This estimate has also not been corrected for animals missed on 
the trackline. The majority of the sightings were in the Aleutian 
Islands, rather than in the Gulf of Alaska, and in water shallower than 
200 m. So few minke whales were seen during three offshore Gulf of 
Alaska surveys for cetaceans in 2009, 2013, and 2015 that a population 
estimate for this species in this area could not be determined (Rone et 
al., 2017).

Humpback Whale

    The humpback whale is distributed worldwide in all ocean basins and 
a broad geographical range from tropical to temperate waters in the 
Northern Hemisphere and from tropical to near-ice-edge waters in the 
Southern Hemisphere. The humpback whales that forage throughout British 
Colombia and Southeast Alaska undertake seasonal migrations from their 
tropical calving and breeding grounds in winter to their high-latitude 
feeding grounds in summer. They may be seen at any time of year in 
Alaska, but most animals winter in temperate or tropical waters near 
Hawaii. In the spring, the animals migrate back to Alaska where food is 
abundant.
    Within Southeast Alaska, humpback whales are found throughout all 
major waterways and in a variety of habitats, including open-ocean 
entrances, open-strait environments, near-shore waters, area with 
strong tidal currents, and secluded bays and inlets. They tend to 
concentrate in several areas, including northern Southeast Alaska. 
Patterns of occurrence likely follow the spatial and temporal changes 
in prey abundance and distribution with humpback whales adjusting their 
foraging locations to areas of high prey density (Clapham 2000).
    Humpback whales may be found in and around Chichagof Island, Icy 
Strait, and Port Frederick Inlet at any given time. While many humpback 
whales migrate to tropical calving and breeding grounds in winter, they 
have been observed in Southeast Alaska in all months of the year 
(Bettridge et al., 2015). Diet for humpback whales in the Glacier Bay/
Icy Strait area mainly consists of small schooling fish (capelin, 
juvenile walleye pollock, sand lance, and Pacific herring) rather than 
euphausiids (krill). They migrate to the northern reaches of Southeast 
Alaska (Glacier Bay) during spring and early summer following these 
fish and then move south towards Stephens Passage in early fall to feed 
on krill, passing the project area on the way (Krieger and Wing 1986). 
Over 32 years of humpback whale monitoring in the Glacier Bay/Icy 
Strait area reveals a substantial decline in population since 2014; a 
total of 164 individual whales were documented in 2016 during surveys 
conducted from June-August, making it the lowest count since 2008 
(Neilson et al., 2017)
    During construction of the first Icy Strait cruise ship berth from 
June 2015 through January 2016, humpback whales were observed in the 
action area on 84 of the 135 days of monitoring; most often in 
September and October. Up to 18 humpback sightings were reported on a 
single day (October 2, 2015), and a total of 226 Level B harassments 
were recorded during project construction (June 2015 through January 
2016) (BergerABAM 2016).

Gray Whale

    Gray whales are found exclusively in the North Pacific Ocean. The 
Eastern North Pacific stock of gray whales inhabit the Chukchi, 
Beaufort, and Bering Seas in northern Alaska in the summer and fall and 
California and Mexico in the winter months, with a migration route 
along the coastal waters of Southeast Alaska. Gray whales have also 
been observed feeding in waters off Southeast Alaska during the summer 
(NMFS 2018e).
    The migration pattern of gray whales appears to follow a route 
along the western coast of Southeast Alaska, traveling northward from 
British Columbia through Hecate Strait and Dixon Entrance, passing the 
west coast of Chichagof Island from late March to May (Jones et al. 
1984, Ford et al. 2013). Since the project area is on the east coast of 
Chichagof Island it is less likely there will be gray whales sighted 
during project construction; however, the possibility exists.
    During the 2016 construction of the first cruise ship terminal at 
Icy Strait Point, no gray whales were seen during the 135-day 
monitoring period (June 2015 through January 2016) (BergerABAM 2016).

Killer Whale

    Killer whales have been observed in all oceans and seas of the 
world, but the highest densities occur in colder and more productive 
waters found at high latitudes. Killer whales are found throughout the 
North Pacific and occur along the entire Alaska coast, in British 
Columbia and Washington inland waterways, and along the outer coasts of 
Washington, Oregon, and California (NMFS 2018f).
    The Alaska Resident stock occurs from Southeast Alaska to the 
Aleutian Islands and Bering Sea. The Northern Resident stock occurs 
from Washington State through part of Southeast Alaska; and the West 
Coast Transient stock occurs from California through Southeast Alaska 
(Muto et al., 2018) and are thought to occur frequently in Southeast 
Alaska (Straley 2017).
    Transient killer whales can pass through the waters surrounding 
Chichagof Island, in Icy Strait and Glacier Bay, feeding on marine 
mammals. Because of their transient nature, it is difficult to predict 
when they will be present in the area. Whales from the Alaska Resident 
stock and the Northern Resident stock are thought to primarily feed on 
fish. Like the transient killer whales, they can pass through Icy 
Strait at any given time (North Gulf Oceanic Society 2018).
    Killer whales were observed on 11 days during construction of the 
first Icy Strait cruise ship berth during the 135-day monitoring period 
(June 2015 through January 2016). Killer whales were observed a few 
times a month. Usually a singular animal was observed, but a group 
containing 8 individuals was seen in the action area on one occasion, 
for a total of 24 animals observed during in-water work (BergerABAM 
2016).

[[Page 18501]]

Pacific White-Sided Dolphin

    Pacific white-sided dolphins are a pelagic species. They are found 
throughout the temperate North Pacific Ocean, north of the coasts of 
Japan and Baja California, Mexico (Muto et al., 2018). They are most 
common between the latitudes of 38[deg] North and 47[deg] North (from 
California to Washington). The distribution and abundance of Pacific 
white-sided dolphins may be affected by large-scale oceanographic 
occurrences, such as El Ni[ntilde]o, and by underwater acoustic 
deterrent devices (NPS 2018a).
    No Pacific white-sided dolphins were observed during construction 
of the first cruise ship berth during the 135-day monitoring period 
(June 2015 through January 2016) (BergerABAM 2016). They are rare in 
the action area, likely because they are pelagic and prefer more open 
water habitats than are found in Icy Strait and Port Frederick Inlet. 
Pacific white-sided dolphins have been observed in Alaska waters in 
groups ranging from 20 to 164 animals, with the sighting of 164 animals 
occurring in Southeast Alaska near Dixon Entrance (Muto et al., 2018).

Dall's Porpoise

    Dall's porpoises are widely distributed across the entire North 
Pacific Ocean. They show some migration patterns, inshore and offshore 
and north and south, based on morphology and type, geography, and 
seasonality (Muto et al., 2018). They are common in most of the larger, 
deeper channels in Southeast Alaska and are rare in most narrow 
waterways, especially those that are relatively shallow and/or with no 
outlets (Jefferson et al., 2019). In Southeast Alaska, abundance varies 
with season.
    Jefferson et al. (2019) recently published a report with survey 
data spanning from 1991 to 2012 that studied Dall's porpoise density 
and abundance in Southeast Alaska. They found Dall's porpoise were most 
abundant in spring, observed with lower numbers in summer, and lowest 
in fall. Surveys found Dall's porpoise to be common in Icy Strait and 
sporadic with very low densities in Port Frederick (Jefferson et al., 
2019). During a 16-year survey of cetaceans in Southeast Alaska, Dall's 
porpoises were commonly observed during spring, summer, and fall in the 
nearshore waters of Icy Strait (Dahlheim et al., 2009). Dall's 
porpoises were observed on two days during the 135-day monitoring 
period (June 2015 through January 2016) of the construction of the 
first cruise ship berth (BergerABAM 2016). Both were single individuals 
transiting within the waters of Port Frederick in the vicinity of 
Halibut Island. Dall's porpoises generally occur in groups from 2-12 
individuals (NMFS 2018g).

Harbor Porpoise

    In the eastern North Pacific Ocean, the Bering Sea and Gulf of 
Alaska harbor porpoise stocks range from Point Barrow, along the Alaska 
coast, and the west coast of North America to Point Conception, 
California. The Southeast Alaska stock ranges from Cape Suckling, 
Alaska to the northern border of British Columbia. Within the inland 
waters of Southeast Alaska, harbor porpoises' distribution is clustered 
with greatest densities observed in the Glacier Bay/Icy Strait region 
and near Zarembo and Wrangell Islands and the adjacent waters of Sumner 
Strait (Dahlheim et al., 2015). Harbor porpoises also were observed 
primarily between June and September during construction of the Huna 
Berth I cruise ship terminal project. Harbor porpoises were observed on 
19 days during the 135-day monitoring period (June 2015 through January 
2016) (BergerABAM 2016) and seen either singularly or in groups from 
two to four animals.
    There is no official stock abundance associated with the SARS for 
harbor porpoise. Both aerial and vessel based surveys have been 
conducted for this species. Aerial surveys of this stock were conducted 
in June and July 1997 and resulted in an observed abundance estimate of 
3,766 harbor porpoise (Hobbs and Waite 2010) and the surveys included a 
subset of smaller bays and inlets. Correction factors for observer 
perception bias and porpoise availability at the surface were used to 
develop an estimated corrected abundance of 11,146 harbor porpoise in 
the coastal and inside waters of Southeast Alaska (Hobbs and Waite 
2010). Vessel based spanning the 22-year study (1991-2012) found the 
relative abundance of harbor porpoise varied in the inland waters of 
Southeast Alaska. Abundance estimated in 1991-1993 (N = 1,076; 95% CI = 
910-1,272) was higher than the estimate obtained for 2006-2007 (N = 
604; 95% CI = 468-780) but comparable to the estimate for 2010-2012 (N 
= 975; 95% CI = 857-1,109; Dahlheim et al., 2015). These estimates 
assume the probability of detection directly on the trackline to be 
unity (g(0) = 1) because estimates of g(0) could not be computed for 
these surveys. Therefore, these abundance estimates may be biased low 
to an unknown degree. A range of possible g(0) values for harbor 
porpoise vessel surveys in other regions is 0.5-0.8 (Barlow 1988, Palka 
1995), suggesting that as much as 50 percent of the porpoise can be 
missed, even by experienced observers.
    Further, other vessel based survey data (2010-2012) for the inland 
waters of Southeast Alaska, calculated abundance estimates for the 
concentrations of harbor porpoise in the northern and southern regions 
of the inland waters (Dahlheim et al. 2015). The resulting abundance 
estimates are 398 harbor porpoise (CV = 0.12) in the northern inland 
waters (including Cross Sound, Icy Strait, Glacier Bay, Lynn Canal, 
Stephens Passage, and Chatham Strait) and 577 harbor porpoise (CV = 
0.14) in the southern inland waters (including Frederick Sound, Sumner 
Strait, Wrangell and Zarembo Islands, and Clarence Strait as far south 
as Ketchikan). Because these abundance estimates have not been 
corrected for g(0), these estimates are likely underestimates.
    The vessel based surveys are not complete coverage of harbor 
porpoise habitat and not corrected for bias and likely underestimate 
the abundance. Whereas, the aerial survey in 1997, although outdated, 
had better coverage of the range and is likely to be more of an 
accurate representation of the stock abundance (11,146 harbor porpoise) 
in the coastal and inside waters of Southeast Alaska.

Harbor Seal

    Harbor seals range from Baja California north along the west coasts 
of Washington, Oregon, California, British Columbia, and Southeast 
Alaska; west through the Gulf of Alaska, Prince William Sound, and the 
Aleutian Islands; and north in the Bering Sea to Cape Newenham and the 
Pribilof Islands. They haul out on rocks, reefs, beaches, and drifting 
glacial ice and feed in marine, estuarine, and occasionally fresh 
waters. Harbor seals are generally non-migratory and, with local 
movements associated with such factors as tide, weather, season, food 
availability and reproduction.
    Distribution of the Glacier Bay/Icy Strait stock, the only stock 
considered in this application, ranges along the coast from Cape 
Fairweather and Glacier Bay south through Icy Strait to Tenakee Inlet 
on Chichagof Island (Muto et al., 2018).
    The Glacier Bay/Icy Strait stock of harbor seals are common 
residents of the action area and can occur on any given day in the 
area, although they tend to be more abundant during the fall months 
(Womble and Gende 2013). A total of 63 harbor seals were seen during 19 
days of the 135-day monitoring period (June 2015 through January 2016)

[[Page 18502]]

(BergerABAM 2016), while none were seen during the 2018 test pile 
program (SolsticeAK 2018). Harbor seals were primarily observed in 
summer and early fall (June to September). Harbor seals were seen 
singulary and in groups of two or more, but on one occasion, 22 
individuals were observed hauled out on Halibut Rock, across Port 
Frederick approximately 1.5 miles from the location of pile 
installation activity (BergerABAM 2016).
    There are two known harbor seal haulouts within the project area. 
According to the AFSC list of harbor seal haulout locations, the 
closest listed haulout (id 1,349: name CF39A) is located in Port 
Frederick, approximately 1,850 m west (AFSC 2018). The group of 22 
animals was observed using Halibut Rock (approximately 2,000 m from any 
potential pile-driving activities) as a haulout.

Steller Sea Lion

    Steller sea lions range along the North Pacific Rim from northern 
Japan to California, with centers of abundance in the Gulf of Alaska 
and Aleutian Islands (Loughlin et al., 1984).
    Of the two Steller sea lion populations in Alaska, the Eastern DPS 
includes sea lions born on rookeries from California north through 
Southeast Alaska and the Western DPS includes those animals born on 
rookeries from Prince William Sound westward, with an eastern boundary 
set at 144[deg] W (NMFS 2018h). Both WDPS and EDPS Steller sea lions 
are considered in this application because the WDPS are common within 
the geographic area under consideration (north of Summer Strait) (Fritz 
et al., 2013, NMFS 2013).
    Steller sea lions are not known to migrate annually, but 
individuals may widely disperse outside of the breeding season (late-
May to early-July), leading to intermixing of stocks (Jemison et al. 
2013; Allen and Angliss 2015).
    Steller sea lions are common in the inside waters of Southeast 
Alaska. They are residents of the project vicinity and are common year-
round in the action area, moving their haulouts based on seasonal 
concentrations of prey from exposed rookeries nearer the open Pacific 
Ocean during the summer to more protected sites in the winter (Alaska 
Department of Fish & Game (ADF&G) 2018). During the construction of the 
existing Icy Strait cruise ship berth a total of 180 Steller sea lions 
were observed on 47 days of the 135 monitoring days, amounting to an 
average of 1.3 sightings per day (BergerABAM 2016). Steller sea lions 
were frequently observed in groups of two or more individuals, but lone 
individuals were also observed regularly (BergerABAM 2016). During a 
test pile program performed at the project location by the Hoonah 
Cruise Ship Dock Company in May 2018, a total of 15 Steller sea lions 
were seen over the course of 7 hours in one day (SolsticeAK 2018). They 
can occur in groups of 1-10 animals, but may congregate in larger 
groups near rookeries and haulouts (NMFS 2018h). No documented 
rookeries or haulouts are near the project area.
    Critical habitat has been defined in Southeast Alaska at major 
haulouts and major rookeries (50 CFR 226.202). The nearest rookery is 
on the White Sisters Islands near Sitka and the nearest major haulouts 
are at Benjamin Island, Cape Cross, and Graves Rocks. The White Sisters 
rookery is located on the west side of Chichagof Island, about 72 km 
southwest of the project area. Benjamin Island is about 60 km northeast 
of Hoonah. Cape Cross and Graves Rocks are both about 70 km west of 
Hoonah. Steller sea lions are known to haul out on land, docks, buoys, 
and navigational markers. However, during the summer months when the 
proposed project would be constructed Steller sea lions are less likely 
to be in the protected waters around the project area, preferring 
exposed rookeries on the western shores of Southeast Alaska.

Sperm Whales

    Tagged sperm whales have been tracked within the Gulf of Alaska, 
and multiple whales have been tracked in Chatham Strait, in Icy Strait, 
and in the action area in 2014 and 2015 (https://seaswap.info/whaletrackerAccessed4/15/19). Tagging studies primarily show that sperm 
whales use the deep water slope habitat extensively for foraging 
(Mathias et al., 2012). Interaction studies between sperm whales and 
the longline fishery have been focused along the continental slope of 
the eastern Gulf of Alaska in water depths between about 1,970 and 
3,280 ft (600 and 1,000 m) (Straley et al. 2005, Straley et al. 2014). 
The known sperm whale habitat (these shelf-edge/slope waters of the 
Gulf of Alaska) are far outside of the action area.
    Also, more recently in November 2018 (4 whales) and March 2019 (2 
whales), sperm whales have been observed in southern Lynn Canal, and on 
March 20, 2019, NMFS performed a necropsy on a sperm whale that died 
from trauma consistent with a ship strike. However, NMFS believes is 
highly unlikely that sperm whales will occur in the action area where 
pile driving activities will occur because they are generally found in 
far deeper waters than those in which the project will occur. 
Therefore, sperm whales are not being proposed for take authorization 
and not discussed further.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 2.

           Table 2--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen         7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).

[[Page 18503]]

 
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Nine marine mammal species (7 cetacean and 2 pinniped (1 otariid and 1 
phocid) species) have the reasonable potential to occur during the 
proposed activities. Please refer to Table 2. Of the cetacean species 
that may be present, three are classified as low-frequency cetaceans 
(i.e., all mysticete species), two are classified as mid-frequency 
cetaceans (i.e., all delphinid species), and two are classified as 
high-frequency cetaceans (i.e., harbor porpoise and Dall's porpoise).
Potential Effects of Specified Activities on Marine Mammals and their 
Habitat
    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take by Incidental Harassment section 
later in this document includes a quantitative analysis of the number 
of individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take by Incidental Harassment 
section, and the Proposed Mitigation section, to draw conclusions 
regarding the likely impacts of these activities on the reproductive 
success or survivorship of individuals and how those impacts on 
individuals are likely to impact marine mammal species or stocks.
    Acoustic effects on marine mammals during the specified activity 
can occur from vibratory and impact pile driving as well as during 
socketing and anchoring of the piles. The effects of underwater noise 
from DPD's proposed activities have the potential to result in Level B 
behavioral harassment of marine mammals in the vicinity of the action 
area.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see, e.g., Au and Hastings (2008); Richardson et al. (1995); 
Urick (1983).
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks or corresponding points of a sound wave 
(length of one cycle). Higher frequency sounds have shorter wavelengths 
than lower frequency sounds, and typically attenuate (decrease) more 
rapidly, except in certain cases in shallower water. Amplitude is the 
height of the sound pressure wave or the ``loudness'' of a sound and is 
typically described using the relative unit of the decibel (dB). A 
sound pressure level (SPL) in dB is described as the ratio between a 
measured pressure and a reference pressure (for underwater sound, this 
is 1 microPascal ([mu]Pa)), and is a logarithmic unit that accounts for 
large variations in amplitude; therefore, a relatively small change in 
dB corresponds to large changes in sound pressure. The source level 
(SL) represents the SPL referenced at a distance of 1 m from the source 
(referenced to 1 [mu]Pa), while the received level is the SPL at the 
listener's position (referenced to 1 [mu]Pa).
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy in a stated frequency band over a stated 
time interval or event, and considers both intensity and duration of 
exposure. The per-pulse SEL is calculated over the time window 
containing the entire pulse (i.e., 100 percent of the acoustic energy). 
SEL is a cumulative metric; it can be accumulated over a single pulse, 
or calculated over periods containing multiple pulses. Cumulative SEL 
represents the total energy accumulated by a receiver over a defined 
time window or during an event. Peak sound pressure (also referred to 
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source, and is represented in the same units as the rms sound pressure.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams or may radiate in all directions 
(omnidirectional sources), as is the case for sound produced by the 
pile driving activity considered here. The compressions and 
decompressions associated with sound waves are detected as changes in 
pressure by aquatic life and man-made sound receptors such as 
hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater

[[Page 18504]]

environment is typically loud due to ambient sound, which is defined as 
environmental background sound levels lacking a single source or point 
(Richardson et al., 1995). The sound level of a region is defined by 
the total acoustical energy being generated by known and unknown 
sources. These sources may include physical (e.g., wind and waves, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic (e.g., 
vessels, dredging, construction) sound. A number of sources contribute 
to ambient sound, including wind and waves, which are a main source of 
naturally occurring ambient sound for frequencies between 200 hertz 
(Hz) and 50 kilohertz (kHz) (Mitson, 1995). In general, ambient sound 
levels tend to increase with increasing wind speed and wave height. 
Precipitation can become an important component of total sound at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times. Marine mammals can contribute significantly to ambient sound 
levels, as can some fish and snapping shrimp. The frequency band for 
biological contributions is from approximately 12 Hz to over 100 kHz. 
Sources of ambient sound related to human activity include 
transportation (surface vessels), dredging and construction, oil and 
gas drilling and production, geophysical surveys, sonar, and 
explosions. Vessel noise typically dominates the total ambient sound 
for frequencies between 20 and 300 Hz. In general, the frequencies of 
anthropogenic sounds are below 1 kHz and, if higher frequency sound 
levels are created, they attenuate rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human activity) but also on the ability of 
sound to propagate through the environment. In turn, sound propagation 
is dependent on the spatially and temporally varying properties of the 
water column and sea floor, and is frequency-dependent. As a result of 
the dependence on a large number of varying factors, ambient sound 
levels can be expected to vary widely over both coarse and fine spatial 
and temporal scales. Sound levels at a given frequency and location can 
vary by 10-20 decibels (dB) from day to day (Richardson et al., 1995). 
The result is that, depending on the source type and its intensity, 
sound from the specified activity may be a negligible addition to the 
local environment or could form a distinctive signal that may affect 
marine mammals.
    Sounds are often considered to fall into one of two general types: 
Pulsed and non-pulsed (defined in the following). The distinction 
between these two sound types is important because they have differing 
potential to cause physical effects, particularly with regard to 
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see 
Southall et al. (2007) for an in-depth discussion of these concepts. 
The distinction between these two sound types is not always obvious, as 
certain signals share properties of both pulsed and non-pulsed sounds. 
A signal near a source could be categorized as a pulse, but due to 
propagation effects as it moves farther from the source, the signal 
duration becomes longer (e.g., Greene and Richardson, 1988).
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.
    The impulsive sound generated by impact hammers is characterized by 
rapid rise times and high peak levels. Vibratory hammers produce non-
impulsive, continuous noise at levels significantly lower than those 
produced by impact hammers. Rise time is slower, reducing the 
probability and severity of injury, and sound energy is distributed 
over a greater amount of time (e.g., Nedwell and Edwards, 2002; Carlson 
et al., 2005).

Acoustic Effects on Marine Mammals

    We previously provided general background information on marine 
mammal hearing (see ``Description of Marine Mammals in the Area of the 
Specified Activity''). Here, we discuss the potential effects of sound 
on marine mammals.
    Note that, in the following discussion, we refer in many cases to a 
review article concerning studies of noise-induced hearing loss 
conducted from 1996-2015 (i.e., Finneran, 2015). For study-specific 
citations, please see that work. Anthropogenic sounds cover a broad 
range of frequencies and sound levels and can have a range of highly 
variable impacts on marine life, from none or minor to potentially 
severe responses, depending on received levels, duration of exposure, 
behavioral context, and various other factors. The potential effects of 
underwater sound from active acoustic sources can potentially result in 
one or more of the following: Temporary or permanent hearing 
impairment, non-auditory physical or physiological effects, behavioral 
disturbance, stress, and masking (Richardson et al., 1995; Gordon et 
al., 2004; Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et 
al., 2009). The degree of effect is intrinsically related to the signal 
characteristics, received level, distance from the source, and duration 
of the sound exposure. In general, sudden, high level sounds can cause 
hearing loss, as can longer exposures to lower level sounds. Temporary 
or permanent loss of hearing will occur almost exclusively for noise 
within an animal's hearing range. We first describe specific 
manifestations of acoustic effects before providing discussion specific 
to pile driving and removal activities.
    Richardson et al. (1995) described zones of increasing intensity of 
effect that might be expected to occur, in relation to distance from a 
source and assuming that the signal is within an animal's hearing 
range. First is the area within which the acoustic signal would be 
audible (potentially perceived) to the animal but not strong enough to 
elicit any overt behavioral or physiological response. The next zone 
corresponds with the area where the signal is audible to the animal and 
of sufficient intensity to elicit behavioral or physiological 
responsiveness. Third is a zone within which, for signals of high 
intensity, the received level is sufficient to potentially cause 
discomfort or tissue damage to auditory or other systems. Overlaying 
these zones to a certain extent is the

[[Page 18505]]

area within which masking (i.e., when a sound interferes with or masks 
the ability of an animal to detect a signal of interest that is above 
the absolute hearing threshold) may occur; the masking zone may be 
highly variable in size.
    We describe the more severe effects (i.e., certain non-auditory 
physical or physiological effects) only briefly as we do not expect 
that there is a reasonable likelihood that pile driving may result in 
such effects (see below for further discussion). Potential effects from 
explosive impulsive sound sources can range in severity from effects 
such as behavioral disturbance or tactile perception to physical 
discomfort, slight injury of the internal organs and the auditory 
system, or mortality (Yelverton et al., 1973). Non-auditory 
physiological effects or injuries that theoretically might occur in 
marine mammals exposed to high level underwater sound or as a secondary 
effect of extreme behavioral reactions (e.g., change in dive profile as 
a result of an avoidance reaction) caused by exposure to sound include 
neurological effects, bubble formation, resonance effects, and other 
types of organ or tissue damage (Cox et al., 2006; Southall et al., 
2007; Zimmer and Tyack, 2007; Tal et al., 2015). The construction 
activities considered here do not involve the use of devices such as 
explosives or mid-frequency tactical sonar that are associated with 
these types of effects.
    Threshold Shift--Marine mammals exposed to high-intensity sound, or 
to lower-intensity sound for prolonged periods, can experience hearing 
threshold shift (TS), which is the loss of hearing sensitivity at 
certain frequency ranges (Finneran, 2015). TS can be permanent (PTS), 
in which case the loss of hearing sensitivity is not fully recoverable, 
or temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Repeated sound exposure that 
leads to TTS could cause PTS. In severe cases of PTS, there can be 
total or partial deafness, while in most cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans, but such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. PTS typically occurs at exposure levels at least 
several decibels above (a 40-dB threshold shift approximates PTS onset; 
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB 
threshold shift approximates TTS onset; e.g., Southall et al. 2007). 
Based on data from terrestrial mammals, a precautionary assumption is 
that the PTS thresholds for impulse sounds (such as impact pile driving 
pulses as received close to the source) are at least 6 dB higher than 
the TTS threshold on a peak-pressure basis and PTS cumulative sound 
exposure level thresholds are 15 to 20 dB higher than TTS cumulative 
sound exposure level thresholds (Southall et al., 2007). Given the 
higher level of sound or longer exposure duration necessary to cause 
PTS as compared with TTS, it is considerably less likely that PTS could 
occur.
    TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. Few data 
on sound levels and durations necessary to elicit mild TTS have been 
obtained for marine mammals.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that occurs during a time where ambient noise is lower and there 
are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and three species of pinnipeds (northern elephant 
seal, harbor seal, and California sea lion) exposed to a limited number 
of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (Finneran, 2015). TTS was not observed in trained 
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to 
impulsive noise at levels matching previous predictions of TTS onset 
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises 
have a lower TTS onset than other measured pinniped or cetacean species 
(Finneran, 2015). Additionally, the existing marine mammal TTS data 
come from a limited number of individuals within these species. There 
are no data available on noise-induced hearing loss for mysticetes. For 
summaries of data on TTS in marine mammals or for further discussion of 
TTS onset thresholds, please see Southall et al. (2007), Finneran and 
Jenkins (2012), Finneran (2015), and NMFS (2018).
    Behavioral Effects--Behavioral disturbance may include a variety of 
effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. Behavioral responses to sound are highly 
variable and context-specific and any reactions depend on numerous 
intrinsic and extrinsic factors (e.g., species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day), as well as the interplay between factors (e.g., 
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007; 
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not 
only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al., 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). 
Please see Appendices B-C of Southall et al. (2007) for a review of 
studies involving marine mammal behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most

[[Page 18506]]

likely to habituate to sounds that are predictable and unvarying. It is 
important to note that habituation is appropriately considered as a 
``progressive reduction in response to stimuli that are perceived as 
neither aversive nor beneficial,'' rather than as, more generally, 
moderation in response to human disturbance (Bejder et al., 2009). The 
opposite process is sensitization, when an unpleasant experience leads 
to subsequent responses, often in the form of avoidance, at a lower 
level of exposure. As noted, behavioral state may affect the type of 
response. For example, animals that are resting may show greater 
behavioral change in response to disturbing sound levels than animals 
that are highly motivated to remain in an area for feeding (Richardson 
et al., 1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments 
with captive marine mammals have showed pronounced behavioral 
reactions, including avoidance of loud sound sources (Ridgway et al., 
1997; Finneran et al., 2003). Observed responses of wild marine mammals 
to loud pulsed sound sources (typically airguns or acoustic harassment 
devices) have been varied but often consist of avoidance behavior or 
other behavioral changes suggesting discomfort (Morton and Symonds, 
2002; see also Richardson et al., 1995; Nowacek et al., 2007). However, 
many delphinids approach low-frequency airgun source vessels with no 
apparent discomfort or obvious behavioral change (e.g., Barkaszi et 
al., 2012), indicating the importance of frequency output in relation 
to the species' hearing sensitivity.
    Available studies show wide variation in response to underwater 
sound; therefore, it is difficult to predict specifically how any given 
sound in a particular instance might affect marine mammals perceiving 
the signal. If a marine mammal does react briefly to an underwater 
sound by changing its behavior or moving a small distance, the impacts 
of the change are unlikely to be significant to the individual, let 
alone the stock or population. However, if a sound source displaces 
marine mammals from an important feeding or breeding area for a 
prolonged period, impacts on individuals and populations could be 
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 
2005). However, there are broad categories of potential response, which 
we describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely and may consist of 
increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive (e.g., Frankel 
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et 
al., 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior 
may reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at the time of the exposure and the 
type and magnitude of the response.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et 
al., 2007; Gailey et al., 2016).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from airgun surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996). The result of a flight response could range from 
brief, temporary exertion and displacement from the area where the 
signal provokes flight to, in extreme cases, marine mammal strandings 
(Evans and England, 2001). However, it should be noted that response to 
a perceived predator does not necessarily invoke flight (Ford and 
Reeves, 2008), and whether individuals are solitary or in groups may 
influence the response.

[[Page 18507]]

    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    Stress Responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle, 1950; 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000; 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found 
that noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003).
    Auditory Masking--Sound can disrupt behavior through masking, or 
interfering with, an animal's ability to detect, recognize, or 
discriminate between acoustic signals of interest (e.g., those used for 
intraspecific communication and social interactions, prey detection, 
predator avoidance, navigation) (Richardson et al., 1995; Erbe et al., 
2016). Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher intensity, and may occur whether the sound is natural (e.g., 
snapping shrimp, wind, waves, precipitation) or anthropogenic (e.g., 
shipping, sonar, seismic exploration) in origin. The ability of a noise 
source to mask biologically important sounds depends on the 
characteristics of both the noise source and the signal of interest 
(e.g., signal-to-noise ratio, temporal variability, direction), in 
relation to each other and to an animal's hearing abilities (e.g., 
sensitivity, frequency range, critical ratios, frequency 
discrimination, directional discrimination, age or TTS hearing loss), 
and existing ambient noise and propagation conditions.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt 
et

[[Page 18508]]

al., 2009). Masking can be reduced in situations where the signal and 
noise come from different directions (Richardson et al., 1995), through 
amplitude modulation of the signal, or through other compensatory 
behaviors (Houser and Moore, 2014). Masking can be tested directly in 
captive species (e.g., Erbe, 2008), but in wild populations it must be 
either modeled or inferred from evidence of masking compensation. There 
are few studies addressing real-world masking sounds likely to be 
experienced by marine mammals in the wild (e.g., Branstetter et al., 
2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand, 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.
    Potential Effects of DPD's Activity--As described previously (see 
``Description of Active Acoustic Sound Sources''), DPD proposes to 
conduct pile driving, including impact and vibratory driving (inclusive 
of socketing and anchoring). The effects of pile driving on marine 
mammals are dependent on several factors, including the size, type, and 
depth of the animal; the depth, intensity, and duration of the pile 
driving sound; the depth of the water column; the substrate of the 
habitat; the standoff distance between the pile and the animal; and the 
sound propagation properties of the environment. With both types, it is 
likely that the pile driving could result in temporary, short term 
changes in an animal's typical behavioral patterns and/or avoidance of 
the affected area. These behavioral changes may include (Richardson et 
al., 1995): changing durations of surfacing and dives, number of blows 
per surfacing, or moving direction and/or speed; reduced/increased 
vocal activities; changing/cessation of certain behavioral activities 
(such as socializing or feeding); visible startle response or 
aggressive behavior (such as tail/fluke slapping or jaw clapping); 
avoidance of areas where sound sources are located; and/or flight 
responses.
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, or reproduction. Significant 
behavioral modifications that could lead to effects on growth, 
survival, or reproduction, such as drastic changes in diving/surfacing 
patterns or significant habitat abandonment are extremely unlikely in 
this area (i.e., shallow waters in modified industrial areas).
    Whether impact or vibratory driving, sound sources would be active 
for relatively short durations, with relation to potential for masking. 
The frequencies output by pile driving activity are lower than those 
used by most species expected to be regularly present for communication 
or foraging. We expect insignificant impacts from masking, and any 
masking event that could possibly rise to Level B harassment under the 
MMPA would occur concurrently within the zones of behavioral harassment 
already estimated for vibratory and impact pile driving, and which have 
already been taken into account in the exposure analysis.

Anticipated Effects on Marine Mammal Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals except the actual footprint of 
the project. The footprint of the project is small, and equal to the 
area of the cruise ship berth and associated pile placement. The small 
lightering facility nearer to the cannery would not impact any marine 
mammal habitat since its proposed location is in between two existing, 
heavily-traveled docks, and within an active marine commercial and 
tourist area. Over time, marine mammals may be deterred from using 
habitat near the project area, due to an increase in vessel traffic and 
tourist activity in this area. The number of cruise ships traveling to 
Hoonah is expected to increase. Hoonah's increased traffic as a top 
Alaskan cruise port-of-call is already occurring. However, this project 
would decrease small vessel traffic to and from cruise ships unable to 
dock at the existing berth.
    The proposed activities may have potential short-term impacts to 
food sources such as forage fish. The proposed activities could also 
affect acoustic habitat (see masking discussion above), but meaningful 
impacts are unlikely. There are no known foraging hotspots, or other 
ocean bottom structures of significant biological importance to marine 
mammals present in the marine waters in the vicinity of the project 
areas. Therefore, the main impact issue associated with the proposed 
activity would be temporarily elevated sound levels and the associated 
direct effects on marine mammals, as discussed previously. The most 
likely impact to marine mammal habitat occurs from pile driving effects 
on likely marine mammal prey (i.e., fish) near where the piles are 
installed. Impacts to the immediate substrate during installation and 
removal of piles are anticipated, but these would be limited to minor, 
temporary suspension of sediments, which could impact water quality and 
visibility for a short amount of time, but which would not be expected 
to have any effects on individual marine mammals. Impacts to substrate 
are therefore not discussed further.
    Effects to Prey--Sound may affect marine mammals through impacts on 
the abundance, behavior, or distribution of prey species (e.g., 
crustaceans, cephalopods, fish, zooplankton). Marine mammal prey varies 
by species, season, and location and, for some, is not well documented. 
Here, we describe studies regarding the effects of noise on known 
marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009). 
Depending on their hearing anatomy and peripheral sensory structures, 
which vary among species, fishes hear sounds using pressure and 
particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
Hastings and Popper (2005) identified several

[[Page 18509]]

studies that suggest fish may relocate to avoid certain areas of sound 
energy. Additional studies have documented effects of pile driving on 
fish, although several are based on studies in support of large, 
multiyear bridge construction projects (e.g., Scholik and Yan, 2001, 
2002; Popper and Hastings, 2009). Several studies have demonstrated 
that impulse sounds might affect the distribution and behavior of some 
fishes, potentially impacting foraging opportunities or increasing 
energetic costs (e.g., Fewtrell and McCauley, 2012; Pearson et al., 
1992; Skalski et al., 1992; Santulli et al., 1999; Paxton et al., 
2017). However, some studies have shown no or slight reaction to 
impulse sounds (e.g., Pena et al., 2013; Wardle et al., 2001; Jorgenson 
and Gyselman, 2009; Cott et al., 2012). More commonly, though, the 
impacts of noise on fish are temporary.
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours 
for one species. Impacts would be most severe when the individual fish 
is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013).
    The action area supports marine habitat for prey species including 
large populations of anadromous fish including Pacific salmon (five 
species), cutthroat and steelhead trout, and Dolly Varden (NMFS 2018i) 
and other species of marine fish such as halibut, rock sole, sculpins, 
Pacific cod, herring, and eulachon (NMFS 2018j). The most likely impact 
to fish from pile driving activities at the project areas would be 
temporary behavioral avoidance of the area. The duration of fish 
avoidance of an area after pile driving stops is unknown, but a rapid 
return to normal recruitment, distribution and behavior is anticipated. 
In general, impacts to marine mammal prey species are expected to be 
minor and temporary due to the expected short daily duration of 
individual pile driving events and the relatively small areas being 
affected.
    The following essential fish habitat (EFH) species may occur in the 
project area during at least one phase of their lifestage: Chum Salmon 
(Oncorhynchus keta), Pink Salmon (O. gorbuscha), Coho Salmon (O. 
kisutch), Sockeye Salmon (O. nerka), and Chinook Salmon (O. 
tshawytscha). No habitat areas of particular concern or EFH areas 
protected from fishing are identified near the project area (NMFS 
2018i). There are no documented anadromous fish streams in the project 
area. The closest documented anadromous fish steam is approximately 2.5 
miles southeast of the project area (ADF&G 2018a).
    The area impacted by the project is relatively small compared to 
the available habitat in Port Frederick Inlet and Icy Strait. Any 
behavioral avoidance by fish of the disturbed area would still leave 
significantly large areas of fish and marine mammal foraging habitat in 
the nearby vicinity. As described in the preceding, the potential for 
DPD's construction to affect the availability of prey to marine mammals 
or to meaningfully impact the quality of physical or acoustic habitat 
is considered to be insignificant. Effects to habitat will not be 
discussed further in this document.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Except with respect to certain activities not pertinent here, 
section 3(18) of the MMPA defines ``harassment'' as any act of pursuit, 
torment, or annoyance, which (i) has the potential to injure a marine 
mammal or marine mammal stock in the wild (Level A harassment); or (ii) 
has the potential to disturb a marine mammal or marine mammal stock in 
the wild by causing disruption of behavioral patterns, including, but 
not limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).
    Take of marine mammals incidental to DPD's pile driving and removal 
activities (as well as during socketing and anchoring) could occur as a 
result of Level A and Level B harassment. Below we describe how the 
potential take is estimated. As described previously, no mortality is 
anticipated or proposed to be authorized for this activity. Below we 
describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the proposed take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source (e.g., frequency, predictability, duty cycle), the environment 
(e.g., bathymetry), and the receiving animals (hearing, motivation, 
experience, demography, behavioral context) and can be difficult to 
predict (Southall et al., 2007, Ellison et al., 2012). Based on what 
the available science indicates and the practical need to use a 
threshold based on a factor that is both predictable and measurable for 
most activities, NMFS uses a generalized acoustic threshold based on 
received level to estimate the onset of behavioral harassment. NMFS 
predicts that marine mammals are likely to be behaviorally harassed in 
a manner we consider Level B harassment when exposed to underwater 
anthropogenic noise above received levels of 120 dB re 1 [mu]Pa (rms) 
for continuous (e.g., vibratory pile driving) and above 160 dB re 1 
[mu]Pa (rms) for impulsive sources (e.g., impact pile driving). DPD's 
proposed activity includes the use of continuous (vibratory pile 
driving) and impulsive (impact pile driving) sources, and therefore the 
120 and 160 dB re 1 [mu]Pa (rms) are applicable.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different

[[Page 18510]]

marine mammal groups (based on hearing sensitivity) as a result of 
exposure to noise. The technical guidance identifies the received 
levels, or thresholds, above which individual marine mammals are 
predicted to experience changes in their hearing sensitivity for all 
underwater anthropogenic sound sources, and reflects the best available 
science on the potential for noise to affect auditory sensitivity by:
    [ssquf] Dividing sound sources into two groups (i.e., impulsive and 
non-impulsive) based on their potential to affect hearing sensitivity;
    [ssquf] Choosing metrics that best address the impacts of noise on 
hearing sensitivity, i.e., sound pressure level (peak SPL) and sound 
exposure level (SEL) (also accounts for duration of exposure); and
    [ssquf] Dividing marine mammals into hearing groups and developing 
auditory weighting functions based on the science supporting that not 
all marine mammals hear and use sound in the same manner.
    These thresholds were developed by compiling and synthesizing the 
best available science, and are provided in Table 3 below. The 
references, analysis, and methodology used in the development of the 
thresholds are described in NMFS 2018 Technical Guidance, which may be 
accessed at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    DPD's pile driving and removal activity includes the use of 
impulsive (impact pile driving) and non-impulsive (vibratory pile 
driving and removal) sources.

            Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift (Auditory Injury)
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW)..................  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
(Underwater)...........................   LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW).................  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
(Underwater)...........................   LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
Sound Propagation
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

    TL = B * log10(R1/R2), where:

B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log(range)). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log(range)). As is 
common practice in coastal waters, here we assume practical spreading 
loss (4.5 dB reduction in sound level for each doubling of distance). 
Practical spreading is a compromise that is often used under conditions 
where water depth increases as the receiver moves away from the 
shoreline, resulting in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions.
Sound Source Levels
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. There are source level 
measurements available for certain pile types and sizes from the 
similar environments recorded from underwater pile driving projects in 
Alaska (e.g., JASCO Reports--Denes et al., 2017 and Austin et al., 
2016).) that were evaluated and used as proxy sound source levels to 
determine reasonable sound source levels likely result from DPD's pile 
driving and removal activities (Table 4). Many source levels used were 
more conservation as the values were from larger pile sizes.

[[Page 18511]]



                                      Table 4--Assumed Sound Source Levels
----------------------------------------------------------------------------------------------------------------
              Activity                  Sound source level  at 10 meters                Sound source
----------------------------------------------------------------------------------------------------------------
                                         Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
24-in steel pile permanent.........  161.9 SPL............................  The 24-in-diameter source level for
30-in steel pile temporary           161.9 SPL............................   vibratory driving are proxy from
 installation.                       161.9 SPL............................   median measured source levels from
30-in steel pile removal...........  161.9 SPL............................   pile driving of 30-in-diameter
30-in steel pile permanent                                                   piles to construct the Ketchikan
 installation.                                                               Ferry Terminal (Denes et al., 2016,
                                                                             Table 72).
36-in steel pile permanent.........  168.2 SPL............................  The 36-in and 42-in pile source
42-in steel pile permanent.........  168.2 SPL............................   level is a proxy from median
                                                                             measured source level from
                                                                             vibratory hammering of 48-in piles
                                                                             for the Port of Anchorage test pile
                                                                             project (Austin et al., 2016).
----------------------------------------------------------------------------------------------------------------
                                             Impact Pile Driving 5 6
----------------------------------------------------------------------------------------------------------------
36-in steel pile permanent.........  186.7 SEL/198.6 SPL..................  The 36-in and 42-in diameter pile
42-in steel pile permanent.........  186.7 SEL/198.6 SPL..................   source level is a proxy from median
                                                                             measured source level from impact
                                                                             hammering of 48-in piles for the
                                                                             Port of Anchorage test pile project
                                                                             (Austin et al., 2016).
----------------------------------------------------------------------------------------------------------------
                                           Socketed Pile Installation
----------------------------------------------------------------------------------------------------------------
24-in steel pile permanent.........  166.2 SPL............................  The socketing and rock anchor source
30-in steel pile temporary.........  166.2 SPL............................   level is a proxy from median
                                                                             measured source level from down-
                                                                             hole drilling of 24-in-diameter
                                                                             piles to construct the Kodiak Ferry
                                                                             Terminal (Denes et al., 2016, Table
                                                                             72).
----------------------------------------------------------------------------------------------------------------
                                            Rock Anchor Installation
----------------------------------------------------------------------------------------------------------------
8-in anchor permanent (for 24-in     166.2 SPL............................  The socketing and rock anchor source
 piles).                             166.2 SPL............................   level is a proxy from median
33-in anchor permanent (for 36-in    166.2 SPL............................   measured source level from down-
 piles).                                                                     hole drilling of 24-in-diameter
33-in anchor permanent (for 42-in                                            piles to construct the Kodiak Ferry
 piles).                                                                     Terminal (Denes et al., 2016, Table
                                                                             72).
----------------------------------------------------------------------------------------------------------------
Notes: Denes et al., 2016--Alaska Department of Transportation's Hydroacoustic Pile Driving Noise Study--
  Comprehensive Report and Austin et al., 2016--Hydroacoustic Monitoring Report: Anchorage Port Modernization
  Project Test Pile Program. Version 3.0. Technical report by JASCO Applied Sciences for Kiewit Infrastructure
  West Co.

Level A Harassment

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources (such as from 
impact and vibratory pile driving), NMFS User Spreadsheet predicts the 
closest distance at which, if a marine mammal remained at that distance 
the whole duration of the activity, it would not incur PTS. Inputs used 
in the User Spreadsheet (Tables 5 and 6), and the resulting isopleths 
are reported below (Table 7).

                  Table 5--NMFS Technical Guidance (2018) User Spreadsheet Input To Calculate PTS Isopleths for Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 User spreadsheet input--vibratory pile driving/anchoring and socketing Spreadsheet Tab A.1 vibratory pile driving used
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        30-in piles  30-in piles                                                               24-in and
                                           24-in piles   (temporary   (temporary  30-in piles  36-in piles  42-in piles     8-in      33-in      30-in
                                           (permanent)    install)     removal)   (permanent)  (permanent)  (permanent)  anchoring  anchoring  socketing
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL)...................        161.9        161.9        161.9        161.9        168.2        168.2      166.2      166.2      166.2
Weighting Factor Adjustment (kHz)........          2.5          2.5          2.5          2.5          2.5          2.5        2.5        2.5        2.5
Number of piles within 24-hr period......            4            6            6            2            2            2          1          2          2
Duration to drive a single pile (min)....           10           20           10           30           30           60         60        240         60
Propagation (xLogR)......................           15           15           15           15           15           15         15         15         15
Distance of source level measurement                10           10           10           10           10           10         10         10
 (meters)*...............................
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 18512]]


    Table 6--NMFS Technical Guidance (2018) User Spreadsheet Input To
             Calculate PTS Isopleths for Impact Pile Driving
------------------------------------------------------------------------
 User spreadsheet input--impact pile driving Spreadsheet Tab E.1 impact
                            pile driving used
-------------------------------------------------------------------------
                                            36-in piles     42-in piles
                                            (permanent)     (permanent)
------------------------------------------------------------------------
Source Level (Single Strike/shot SEL)...           186.7           186.7
Weighting Factor Adjustment (kHz).......               2               2
Number of strikes per pile..............             100             135
Number of piles per day.................               4               2
Propagation (xLogR).....................              15              15
Distance of source level measurement                  10              10
 (meters)...............................
------------------------------------------------------------------------


                     Table 7--NMFS Technical Guidance (2018) User Spreadsheet Outputs To Calculate Level A Harassment PTS Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         User spreadsheet output                                                      PTS isopleths (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Level A harassment
                                                                         -------------------------------------------------------------------------------
                 Activity                    Sound source level at 10 m                                        High-
                                                                          Low- frequency  Mid- frequency     frequency        Phocid          Otariid
                                                                             cetaceans       cetaceans       cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel installation..................  161.9 SPL \1\...............             6.0             0.5             8.8             3.6             0.3
30-in steel temporary installation........  161.9 SPL \1\...............            12.4             1.1            18.4             7.6             0.5
30-in steel removal.......................  161.9 SPL \1\...............             7.8             0.7            11.6             4.8             0.3
30-in steel permanent installation........  161.9 SPL \1\...............             7.8             0.7            11.6             4.8             0.3
36-in steel permanent installation........  168.2 SPL \2\...............            20.6             1.8            30.5            12.5             0.9
42-in steel permanent installation........  168.2 SPL \2\...............            32.7             2.9            48.4            19.9             1.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel permanent installation........  186.7 SEL/198.6 SPL \2\.....           956.7            34.0         1,139.6           512.0            37.3
42-in steel permanent installation........  186.7 SEL/198.6 SPL \2\.....           736.2            26.2           876.9           394.0            28.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Socketed Pile Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel permanent installation........  166.2 SPL \3\...............            24.1             2.1            35.6            14.6             1.0
30-in steel temporary installation........  166.2 SPL \3\...............            24.1             2.1            35.6            14.6             1.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Rock Anchor Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
8-in anchor permanent installation (for 24- 166.2 SPL \3\...............            15.2             1.3            22.4             9.2             0.6
 in piles).
33-in anchor permanent installation (for    166.2 SPL \3\...............            60.7             5.4            89.7            36.9             2.6
 36-in piles).
33-in anchor permanent installation (for    166.2 SPL \3\...............            60.7             5.4            89.7            36.9             2.6
 42-in piles).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The 24-in and 30-in-diameter source levels for vibratory driving are proxy from median measured source levels from pile driving of 30-in-diameter
  piles to construct the Ketchikan Ferry Terminal (Denes et al. 2016, Table 72).
\2\ The 36-in and 42-in-diameter pile source levels are proxy from median measured source levels from pile driving (vibratory and impact hammering) of
  48-in piles for the Port of Anchorage test pile project (Austin et al. 2016, Tables 9 and 16). We calculated the distances to impact pile driving
  Level A harassment thresholds for 36-in piles assuming 100 strikes per pile and a maximum of 4 piles installed in 24 hours; for 42-in piles we assumed
  135 strikes per pile and a maximum of 2 piles installed in 24 hours.
\3\ The socketing and rock anchoring source level is proxy from median measured sources levels from down-hole drilling of 24-in-diameter piles to
  construct the Kodiak Ferry Terminal (Denes et al. 2016, Table 72).

Level B Harassment
    Utilizing the practical spreading loss model, DPD determined 
underwater noise will fall below the behavioral effects threshold of 
120 dB rms for marine mammals at the distances shown in Table 8 for 
vibratory pile driving/removal, socketing, and rock anchoring. With 
these radial distances, and due to the occurrence of landforms (See 
Figure 8, 12, 13 of IHA Application), the largest Level B Harassment 
Zone calculated for vibratory pile driving for 36-in and 42-in steel 
piles equaled 193 km\2\ and socket and rock anchoring equaled 116 
km\2\. For calculating the Level B Harassment Zone for impact driving, 
the practical spreading loss model was used with a behavioral threshold 
of 160 dB rms. The maximum radial distance of the Level B Harassment 
Zone for impact piling equaled 3,744 meters. At this radial distance, 
the entire Level B Harassment Zone for impact piling equaled 19 km\2\. 
Table 8 below provides all Level B Harassment radial distances

[[Page 18513]]

(m) and their corresponding areas (km\2\) during DPD's proposed 
activities.

   Table 8--Radial Distances (Meters) to Relevant Behavioral Isopleths and Associated Ensonified Areas (Square
                                 Kilometers) Using the Practice Spreading Model
----------------------------------------------------------------------------------------------------------------
                                                                                                      Level B
              Activity                 Received level at 10 meters   Level B harassment zone (m)    harassment
                                                                                  *                zone (km\2\)
----------------------------------------------------------------------------------------------------------------
                                         Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
24-in steel installation............  161.9 SPL \3\...............  6,215 (calculated 6,213)....        39 km\2\
30-in steel temporary installation..  161.9 SPL \3\...............  6,215 (calculated 6,213).
30-in steel removal.................  161.9 SPL \3\...............  6,215 (calculated 6,213).
30-in steel permanent installation..  161.9 SPL \3\...............  6,215 (calculated 6,213).
36-in steel permanent installation..  168.2 SPL \4\...............  16,345 (calculated 16,343)..       193 km\2\
42-in steel permanent installation..  168.2 SPL \4\...............  16,345 (calculated 16,343).
----------------------------------------------------------------------------------------------------------------
                                             Impact Pile Driving 5 6
----------------------------------------------------------------------------------------------------------------
36-in steel permanent installation..  186.7 SEL/198.6 SPL \4\.....  3,745 (calculated 3,744)....        19 km\2\
42-in steel permanent installation..  186.7 SEL/198.6 SPL \4\.....  3,745 (calculated 3,744).
----------------------------------------------------------------------------------------------------------------
                                           Socketed Pile Installation
----------------------------------------------------------------------------------------------------------------
24-in steel permanent installation..  166.2 SPL \7\...............  12,025 (calculated 12,023)..       116 km\2\
30-in steel temporary installation..  166.2 SPL \7\...............  12,025 (calculated 12,023).
----------------------------------------------------------------------------------------------------------------
                                            Rock Anchor Installation
----------------------------------------------------------------------------------------------------------------
8-in anchor permanent installation    166.2 SPL \7\...............  12,025 (calculated 12,023)..       116 km\2\
 (for 24-in piles).
33-in anchor permanent installation   166.2 SPL \7\...............  12,025 (calculated 12,023).
 (for 36-in piles).
33-in anchor permanent installation   166.2 SPL \7\...............  12,025 (calculated 12,023)..
 (for 42-in piles).
----------------------------------------------------------------------------------------------------------------
* Numbers rounded up to nearest 5 meters.

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. Potential exposures to impact pile driving, vibratory 
pile driving/removal and socketing/rock anchoring noises for each 
acoustic threshold were estimated using group size estimates and local 
observational data. As previously stated, take by Level B harassment as 
well as small numbers of take by Level A harassment will be will be 
considered for this action. Take by Level B and Level A harassment are 
calculated differently for some species based on monthly or daily 
sightings data and average group sizes within the action area using the 
best available data. Take by Level A harassment is being proposed for 
three species where the Level A harassment isopleths are very large 
during impact pile driving (harbor porpoise, harbor seal, and Steller 
sea lion), and is based on average group size multiplied by the number 
of days of impact pile driving. Distances to Level A harassment 
thresholds for other project activities (vibratory pile driving/
removal, socketing, rock anchoring) are considerably smaller compared 
to impact pile driving, and mitigation is expected to avoid Level A 
harassment from these other activities.
Minke Whales
    There are no density estimates of minke whales available in the 
project area. These whales are usually sighted individually or in small 
groups of 2-3, but there are reports of loose aggregations of hundreds 
of animals (NMFS 2018). There was one sighting of a minke whale during 
the 135 days of monitoring during the Huna Berth I construction project 
(June 2015 through January 2016) (BergerABAM 2016). To be conservative, 
we predict that three minke whales in a group could be sighted 3 times 
over the 6-month project period for a total of 9 minke whales that are 
proposed to be taken by Level B harassment.
Humpback Whales
    There are no density estimates of humpback whales available in the 
project area. Humpback whale presence in the action area is likely 
steady through the work period until November, when most humpbacks 
migrate back to Hawaii or Mexico. NMFS has received a few reports of 
humpback whales over-wintering in Southeast Alaska, but numbers of 
animals and exact locations are very hard to predict, and NMFS assumes 
the presence of much fewer humpbacks in the action area in November and 
later winter months. During the previous Huna Berth I project, humpback 
whales were observed on 84 of the 135 days of monitoring; most often in 
September and October (BergerABAM 2016). The best available information 
on the distribution of humpbacks in the project area was obtained from 
several sources including: Icy Strait observations from 2015 
(BergerABAM 2016), Glacier Bay/Icy Strait NPS Survey data 2014-2018 
(provided by NPS, March 2019), Whale Alert opportunistic reported 
sightings 2016-2018, and reported HB whale bubble-net feeding group to 
NPS, 2015-2018 (provided by NPS, March 2019).
    The National Park Service Glacier Bay/Icy Strait survey is designed 
to observe humpback whales and has regular effort in June, July, and 
August. This is the primary data source used to estimate exposures of 
humpback whales

[[Page 18514]]

in the action area during those months, except for when a maximum group 
size reported in Whale Alert data was greater, then the Whale Alert 
number was used (June and July maximum group size). The on-site marine 
mammal monitoring data from BergerABAM (2016) was used to estimate 
takes in September and October and Whale Alert data was the only data 
source available in November and could represent a minimum number of 
observations due to fewer opportunistic sightings recorded in that 
month. In addition, a single group of bubble-net feeding humpbacks of 
10 animals was added to the total estimated exposures for June and 
October, based on anecdotal data provided by NPS of bubble-net feeding 
groups of humpbacks in the action area in those months of construction.
    To estimate the number of exposures, NMFS looked at the proportion 
of days of the month when the numbers of animals observed were within 
one standard deviation of that month's average daily sightings. That 
proportion was 0.7. The average number of sightings was estimated as 
exposures on those days. For the remaining 30 percent of work days, the 
maximum number of observations on any single day were estimated to be 
exposed on those days. For example, in June, the average number of 
daily observations (1.31) was estimated to occur on 70 percent of the 
17 work days, which resulted in 15.59 exposures. On the other 30 
percent of the 17 work days, the maximum number of observations on any 
day (10) resulted in 51 estimated exposures. In addition, in June, NMFS 
estimates that one bubble-net feeding group of 10 individuals could be 
exposed, due to anecdotal evidence of this feeding activity occurring 
inside the proposed action area. NMFS estimates a total of 76.59 
humpback whales could be exposed in June. Humpback whales could be in 
larger groups when large amounts of prey are available, but this is 
difficult to predict with any precision. Although we are not proposing 
to authorize takes by month, we are demonstrating how the total take 
was calculated. The total number of exposures per month was calculated 
to be 76.59 (June), 68.02 (July), 71.93 (August), 132.07 (September), 
78.82 (October), and 6.20 (November). The total proposed whales to be 
taken by Level B harassment from June to November is 434 (433.63) 
humpback whales with 27 of those whales anticipated being from the 
Mexico DPS (0.0601 percentage of the total animals).
Gray Whales
    There are no density estimates of gray whales available in the 
project area. Gray whales travel alone or in small, unstable groups, 
although large aggregations may be seen in feeding and breeding grounds 
(NMFS 2018e). Observations in Glacier Bay and nearby waters recorded 
two gray whales documented over a 10-year period (Keller et al., 2017). 
None were observed during Huna Berth I project monitoring (BergerABAM 
2016). We conservatively estimate a small group to be 3 gray whales x 1 
sighting over the 6-month work period for a total of three gray whale 
proposed to be taken by Level B harassment.
Killer Whales
    There are no density estimates of killer whales available in the 
project area. Killer whales occur commonly in the waters of the project 
area, and could include members of several designated stocks that may 
occur in the vicinity of the proposed project area. Whales are known to 
use the Icy Strait corridor to enter and exit inland waters and are 
observed in every month of the year, with certain pods being observed 
inside Port Frederick passing directly in front of Hoonah. Group size 
of resident killer whale pods in the Icy Strait area ranges from 42 to 
79 and occur in every month of the year (Dahlheim pers. comm. to NMFS 
2015). As determined during a line-transect survey by Dalheim et al. 
(2008), the greatest number of transient killer whale observed occurred 
in 1993 with 32 animals seen over two months for an average of 16 
sightings per month. NMFS estimates that group size of 79 resident 
killer whales and 16 transient killer whales could occur each month 
during the 6-month project period for a total of 570 takes by Level B 
harassment.
Pacific White-Sided Dolphin
    There are no density estimates of Pacific white-sided dolphins 
available in the project area. Pacific white-sided dolphins have been 
observed in Alaska waters in groups ranging from 20 to 164 animals, 
with the sighting of 164 animals occurring in Southeast Alaska near 
Dixon Entrance (Muto et al., 2018). There were no Pacific white-sided 
dolphins observed during the 135-day monitoring period during the Huna 
Berth I project. However, to be conservative NMFS estimates 164 Pacific 
white-sided dolphins may be seen once over the 6-month project period 
for a total of 164 takes by Level B harassment.
Dall's Porpoise
    Little information is available on the abundance of Dall's porpoise 
in the inland waters of Southeast Alaska. Dall's porpoise are most 
abundant in spring, observed with lower numbers in the summer, and 
lowest numbers in fall. Jefferson et al., 2019 presents the first 
abundance estimates for Dall's porpoise in these waters and found the 
abundance in summer (N = 2,680, CV = 19.6 percent), and lowest in fall 
(N = 1,637, CV = 23.3 percent). Dall's porpoise are common in Icy 
Strait and sporadic with very low densities in Port Frederick 
(Jefferson et al., 2019). Dahlheim et al. (2008) observed 346 Dall's 
porpoise in Southeast Alaska (inclusive of Icy Strait) during the 
summer (June/July) of 2007 for an average of 173 animals per month as 
part of a 17-year study period. During the previous Huna Berth I 
project, only two Dall's porpoise were observed, and were transiting 
within the waters of Port Frederick in the vicinity of Halibut Island. 
Therefore, NMFS' estimates 173 Dall's porpoise per month may be seen 
each month of the 6-month project period for a total of 1,038 takes by 
Level B harassment.
Harbor Porpoise
    Dahlheim et al. (2015) observed 332 resident harbor porpoises occur 
in the Icy Strait area, and harbor porpoise are known to use the Port 
Frederick area as part of their core range. During the Huna Berth I 
project monitoring, a total of 32 harbor porpoise were observed over 19 
days during the 4-month project. The harbor porpoises were observed in 
small groups with the largest group size reported was four individuals 
and most group sizes consisting of three or fewer animals. NMFS 
conservatively estimates that 332 harbor porpoises could occur in the 
project area each month over the 6-month project period for a total of 
1,932 takes by Level B harassment. Because the Level A harassment zone 
is significantly larger than the shutdown zone during impact pile 
driving, NMFS predicts that some take by Level A harassment may occur. 
Based on the previous monitoring results, we estimate that a group size 
of four harbor porpoises multiplied by 1 group per day over 8 days of 
impact pile driving would yield a total of 32 takes by Level A 
harassment.
Harbor Seal
    There are no density estimates of harbor seals available in the 
project area. Keller et al. (2017) observed an average of 26 harbor 
seal sightings each month between June and August of 2014

[[Page 18515]]

in Glacier Bay and Icy Strait. During the monitoring of the Huna Berth 
I project, harbor seals typically occur in groups of one to four 
animals and a total of 63 seals were observed during 19 days of the 
135-day monitoring period. NMFS conservatively estimate that 26 harbor 
seals could occur in the project area each month during the 6-month 
project period for a total of 156 takes by Level B harassment. Because 
the Level A harassment zone is significantly larger than the shutdown 
zone during impact pile driving, NMFS predicts that some take by Level 
A harassment may occur. Based on the previous monitoring results, we 
estimate that a group size of two harbor seals multiplied by 1 group 
per day over 8 days of impact pile driving would yield a total of 16 
takes by Level A harassment.
Steller Sea Lion
    There are no density estimates of Steller sea lions available in 
the project area. NMFS expects that Steller sea lion presence in the 
action area will vary due to prey resources and the spatial 
distribution of breeding versus non-breeding season. In April and May, 
Steller sea lions are likely feeding on herring spawn in the action 
area. Then, most Steller sea lions likely move to the rookeries along 
the outside coast (away from the action area) during breeding season, 
and would be in the action area in greater numbers in August and later 
months (J. Womble, NPS, pers. comm. to NMFS AK Regional Office, March 
2019). However, Steller sea lions are also opportunistic predators and 
their presence can be hard to predict.
    Steller sea lions typically occur in groups of 1-10 animals, but 
may congregate in larger groups near rookeries and haulouts. The 
previous Huna Berth I project observed a total of 180 Steller sea lion 
sightings over 135 days in 2015, amounting to an average of 1.3 
sightings per day (BergerABAM 2016). During a test pile program 
performed at the project location by the Hoonah Cruise Ship Dock 
Company in May 2018, a total of 15 Steller sea lions were seen over the 
course of 7 hours in one day (SolsticeAK 2018).
    We used the same process to calculate Steller sea lion take as 
explained above or humpback whales, except that 79 percent of the work 
days in each month are expected to expose the average number of 
animals, and 21 percent of the work days would expose the maximum 
number of animals. For example, in June, the average number of daily 
observations (1.6) was estimated to occur on 13.43 work days, which 
would result in 21.48 exposures. On the other 21 percent of the 17 work 
days, the maximum number of observations on any day (26) could result 
in 92.82 estimated exposures. NMFS estimates a total of 114.31 Steller 
sea lions could be exposed in June. Although we are not proposing to 
authorize takes by month, we are demonstrating how the total take was 
calculated. The total number of exposures per month was calculated to 
be 114.31 (June), 57.19 (July), 92.89 (August), 199.23 (September), 
79.10 (October), and 16.57 (November). Therefore, the total proposed 
Steller sea lions that may be taken by Level B harassment from June to 
November is 559 Steller sea lions with 39 of those sea lions 
anticipated being from the Western DPS (0.0702 percentage of the total 
animals (L. Jemison draft unpublished Steller sea lion data, 2019). 
Because the Level A harassment zone is significantly larger than the 
shutdown zone during impact pile driving, NMFS predicts that some take 
by Level A harassment may occur. Based on the previous monitoring 
results, we estimate that a group size of two Steller sea lions 
multiplied by 1 group per day over 8 days of impact pile driving would 
yield a total of 16 takes by Level A harassment.
    Table 9 below summarizes the proposed estimated take for all the 
species described above as a percentage of stock abundance.

                                           Table 9--Proposed Take Estimates as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Species                      Stock (NEST)            Level A harassment        Level B harassment               Percent of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke Whale.......................  N/A.......................  0.......................  9.......................  N/A
Humpback Whale....................  Hawaii DPS (9,487) \a\....                            406.....................  4.3
                                    Mexico DPS (606) \a\......  0.......................  27......................  4.5
                                                                                          (Total 433).
Gray Whale........................  Eastern North Pacific       0.......................  3.......................  Less than 1 percent
                                     (26,960).
Killer Whale......................  Alaska Resident (2,347)...                            469.....................  19.9 \b\
                                    Northern Resident (261)...  0.......................  52......................  19.9 \b\
                                    West Coast Transient (243)                            49......................  20.2 \b\
                                                                                          (Total 570).
Pacific White-Sided Dolphin.......  North Pacific (26,880)....  0.......................  164.....................  Less than 1 percent
Dall's Porpoise...................  Alaska (83,400) \c\.......  0.......................  1,038...................  1.2
Harbor Porpoise...................  NA........................  32......................  1,932...................  NA
Harbor Seal.......................  Glacier Bay/Icy Strait      16......................  156.....................  2.16
                                     (7,210).
Steller Sea Lion..................  Eastern U.S. (41,638).....  15......................  520.....................  1.25 Less than 1 percent
                                    Western U.S. (53,303).....                            1.......................  39
                                                                (Total 16)..............  (Total 559).............
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Under the MMPA humpback whales are considered a single stock (Central North Pacific); however, we have divided them here to account for DPSs listed
  under the ESA. Using the stock assessment from Muto et al. 2018 for the Central North Pacific stock (10,103 whales) and calculations in Wade et al.
  2016; 9,487 whales are expected to be from the Hawaii DPS and 606 from the Mexico DPS.
\b\ Take estimates are weighted based on calculated percentages of population for each distinct stock, assuming animals present would follow same
  probability of presence in project area.
\c\ Jefferson et al. 2019 presents the first abundance estimates for Dall's porpoise in the waters of Southeast Alaska with highest abundance recorded
  in spring (N = 5,381, CV = 25.4%), lower numbers in summer (N = 2,680, CV = 19.6%), and lowest in fall (N = 1,637, CV = 23.3%). However, NMFS
  currently recognizes a single stock of Dall's porpoise in Alaskan waters and an estimate of 83,400 Dall's porpoises is used by NMFS for the entire
  stock (Muto et al., 2018).

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of

[[Page 18516]]

such species or stock for taking for certain subsistence uses (latter 
not applicable for this action). NMFS regulations require applicants 
for incidental take authorizations to include information about the 
availability and feasibility (economic and technological) of equipment, 
methods, and manner of conducting such activity or other means of 
effecting the least practicable adverse impact upon the affected 
species or stocks and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned); and
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The following mitigation measures are proposed in the IHA:

Timing Restrictions

    All work will be conducted during daylight hours. If poor 
environmental conditions restrict visibility full visibility of the 
shutdown zone, pile installation would be delayed.

Sound Attenuation

    To minimize noise during impact pile driving, pile caps (pile 
softening material) will be used. DPD will use high-density 
polyethylene (HDPE) or ultra-high-molecular-weight polyethylene (UHMW) 
softening material on all templates to eliminate steel on steel noise 
generation.

Shutdown Zone for In-Water Heavy Machinery Work

    For in-water heavy machinery work (using, e.g., movement of the 
barge to the pile location; positioning of the pile on the substrate 
via a crane (i.e., stabling the pile), removal of the pile from the 
water column/substrate via a crane (i.e., deadpull); or placement of 
sound attenuation devices around the piles.) If a marine mammal comes 
within 10 m of such operations, operations shall cease and vessels 
shall reduce speed to the minimum level required to maintain steerage 
and safe working conditions.

Shutdown Zones

    For all pile driving/removal and drilling activities, DPD will 
establish a shutdown zone for a marine mammal species that is greater 
than its corresponding Level A harassment zone; except for a few 
circumstances during impact pile driving, over the course of 8 days, 
where the shutdown zone is smaller than the Level A harassment zone for 
high frequency cetaceans and phocids due to the practicability of 
shutdowns on the applicant and to the potential difficulty of observing 
these animals in the large Level A harassment zones. The calculated PTS 
isopleths were rounded up to a whole number to determine the actual 
shutdown zones that the applicant will operate under (Table 10). The 
purpose of a shutdown zone is generally to define an area within which 
shutdown of the activity would occur upon sighting of a marine mammal 
(or in anticipation of an animal entering the defined area).

                                                                 Table 10--Pile Driving Shutdown Zones During Project Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Shutdown zones (radial distance in meters, area in km\2\)
               Source               ------------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Low-frequency cetaceans         Mid-frequency cetaceans        High-frequency cetaceans               Phocids                        Otariids
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                In-Water Construction Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Barge movements, pile positioning,   10 m (0.00093 km\2\)..........  10 m (0.00093 km\2\)..........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\)
 sound attenuation placement *.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Vibratory Pile Driving/Removal
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel installation (18 piles;  25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\)
 ~40 min per day on 4.5 days).
30-in steel temporary installation   25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\)
 (62 piles; ~2 hours per day on
 10.5 days).
30-in steel removal (62 piles; ~1    25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\)
 hour per day on 10.5 days).
30-in steel permanent installation   25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\)
 (3 piles; ~1 hour per day on 1.5
 days).
36-in steel permanent installation   25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  50 m (0.02307 km\2\).........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\)
 (16 piles; ~1 hour per day on 8
 days).
42-in steel permanent installation   50 m (0.02307 km\2\)..........  10 m (0.00093 km\2\)..........  50 m (0.02307 km\2\).........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\)
 (8 piles; ~2 hours per day on 4
 days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Impact Pile Driving
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel permanent installation   1,000 m (2.31 km\2\)..........  50 m (0.02307 km\2\)..........  100 m* (0.0875 km\2\)........  50 m* (0.02307 km\2\)........  50 m (0.02307 km\2\)
 (16 piles; ~10 minutes per day on
 4 days).
42-in steel permanent installation   750 m (1.44 km\2\)............  50 m (0.02307 km\2\)..........  100 m* (0.0875 km\2\)........  50 m* (0.02307 km\2\)........  50 m (0.02307 km\2\)
 (8 piles; ~6 minutes per day on 4
 days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   Socketed Pile Installation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel permanent installation   25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  50 m (0.02307 km\2\).........  15 m (0.0021 km\2\)..........  10 m (0.00093 km\2\)
 (18 piles; ~2 hours per day on 9
 days).
30-in steel temporary installation   25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  50 m (0.02307 km\2\).........  15 m (0.0021 km\2\)..........  10 m (0.00093 km\2\)
 (up to 10 piles; ~2 hours per day
 on 5 days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 18517]]

 
                                                                                    Rock Anchor Installation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
8-in anchor permanent installation   25 m (0.005763 km\2\).........  10 m (0.00093 km\2\)..........  25 m (0.005763 km\2\)........  10 m (0.00093 km\2\).........  10 m (0.00093 km\2\)
 (for 24-in piles, 2 anchors; ~1
 hour per day on 2 days).
33-in anchor permanent installation  100 m (0.0875 km\2\)..........  10 m (0.00093 km\2\)..........  100 m (0.0875 km\2\).........  50 m (0.02307 km\2\).........  10 m (0.00093 km\2\)
 (for 36- and 42-in piles, 24
 anchors; ~8 hours per day on 12
 days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Due to practicability of the applicant to shutdown and the difficulty of observing some species and low occurrence of some species in the project area, such as high frequency cetaceans or
  pinnipeds out to this distance, the shutdown zones were reduced and Level A harassment takes were requested.

Non-Authorized Take Prohibited

    If a species enters or approaches the Level B zone and that species 
is either not authorized for take or its authorized takes are met, pile 
driving and removal activities must shut down immediately using delay 
and shut-down procedures. Activities must not resume until the animal 
has been confirmed to have left the area or an observation time period 
of 15 minutes has elapsed for pinnipeds and small cetaceans and 30 
minutes for large whales.

Soft Start

    The use of a soft-start procedure are believed to provide 
additional protection to marine mammals by providing warning and/or 
giving marine mammals a chance to leave the area prior to the impact 
hammer operating at full capacity. For impact pile driving, contractors 
will be required to provide an initial set of three strikes from the 
hammer at 40 percent energy, followed by a one-minute waiting period. 
Then two subsequent three strike sets would occur. Soft Start is not 
required during vibratory pile driving and removal activities.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means of 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, requirements pertaining to 
the monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    [ssquf] Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    [ssquf] Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    [ssquf] Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    [ssquf] How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    [ssquf] Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    [ssquf] Mitigation and monitoring effectiveness.

DPD Briefings

    DPD will conduct briefings between construction supervisors and 
crews, marine mammal monitoring team, and DPD staff prior to the start 
of all pile driving activities and when new personnel join the work, in 
order to explain responsibilities, communication procedures, marine 
mammal monitoring protocol, and operational procedures. The crew will 
be requested to alert the PSO when a marine mammal is spotted in the 
action area.

Protected Species Observer Check-In With Construction Crew

    Each day prior to commencing pile driving activities, the lead NMFS 
approved Protected Species Observer (PSO) will conduct a radio check 
with the construction foreman or superintendent to confirm the 
activities and zones to be monitored that day. The construction foreman 
and lead PSO will maintain radio communications throughout the day so 
that the PSOs may be alerted to any changes in the planned construction 
activities and zones to be monitored.

Pre-Activity Monitoring

    Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving of 30 min or longer occurs, PSOs will 
observe the shutdown and monitoring zones for a period of 30 min. The 
shutdown zone will be cleared when a marine mammal has not been 
observed within the zone for that 30-min period. If a marine mammal is 
observed within the shutdown zone, pile driving activities will not 
begin until the animal has left the shutdown zone or has not been 
observed for 15 min. If the Level B Harassment Monitoring Zone has been 
observed for 30 min and no marine mammals (for which take has not been 
authorized) are present within the zone, work can continue even if 
visibility becomes impaired within the Monitoring Zone. When a marine 
mammal permitted for Level B harassment take has been permitted is 
present in the Monitoring zone, piling activities may begin and

[[Page 18518]]

Level B harassment take will be recorded.

Monitoring Zones

    DPD will establish and observe monitoring zones for Level B 
harassment as presented in Table 8. The monitoring zones for this 
project are areas where SPLs are equal to or exceed 120 dB rms (for 
vibratory pile driving/removal and socketing/rock anchoring) and 160 dB 
rms (for impact pile driving). These zones provide utility for 
monitoring conducted for mitigation purposes (i.e., shutdown zone 
monitoring) by establishing monitoring protocols for areas adjacent to 
the shutdown zones. Monitoring of the Level B harassment zones enables 
observers to be aware of and communicate the presence of marine mammals 
in the project area, but outside the shutdown zone, and thus prepare 
for potential shutdowns of activity.

Visual Monitoring

    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after all pile driving/removal and socking/rock anchoring 
activities. In addition, PSO shall record all incidents of marine 
mammal occurrence, regardless of distance from activity, and shall 
document any behavioral reactions in concert with distance from piles 
being driven/removed or during socketing and rock anchoring. Pile 
driving/removal and socketing/anchoring activities include the time to 
install, remove, or socket/rock anchor a single pile or series of 
piles, as long as the time elapsed between uses of the pile driving 
equipment is no more than thirty minutes.
    Monitoring will be conducted by PSOs from on land and from a 
vessel. The number of PSOs will vary from three to four, depending on 
the type of pile driving, method of pile driving and size of pile, all 
of which determines the size of the harassment zones. Monitoring 
locations will be selected to provide an unobstructed view of all water 
within the shutdown zone and as much of the Level B harassment zone as 
possible for pile driving activities. Three PSOs will monitor during 
all impact pile driving activity at the lightering float project site. 
Three PSOs will monitor during all impact pile driving activities at 
the Berth II project site. Three PSOs will monitor during vibratory 
pile driving of 24-in and 30-in steel piles. Four PSOs will monitor 
during vibratory pile driving of 36-in and 42-in steel piles piles and 
during all socketing/rock anchoring activities.
    Three PSOs will monitor during all pile driving activities at the 
lightering float project site, with locations as follows: PSO #1: 
Stationed at or near the site of pile driving; PSO #2: Stationed on 
Long Island (southwest of Hoonah in Port Frederick Inlet) and 
positioned to be able to view west into Port Frederick Inlet and north 
towards the project area; and PSO #3: Stationed on a vessel traveling a 
circuitous route through the Level B monitoring zone.
    Three PSOs will monitor during all impact pile driving activities 
at the Berth II project site, with locations as follows: PSO #1: 
Stationed at or near the site of pile driving; PSO #2: Stationed on 
Halibut Island (northwest of the project site in Port Frederick Inlet) 
and positioned to be able to view east towards Icy Strait and southeast 
towards the project area; and PSO #3: Stationed on a vessel traveling a 
circuitous route through the Level B monitoring zone.
    Three PSOs will monitoring during vibratory pile driving of 24- and 
30-in steel piles at the Berth II project site, with locations as 
follows PSO #1: Stationed at or near the site of pile driving; PSO #2: 
Stationed on Scraggy Island (northwest of the project site in Port 
Frederick Inlet) an positioned to be able to view south towards the 
project area; and PSO#3: Stationed on a vessel traveling a circuitous 
route through the Level B monitoring zone.
    Four PSOs will monitor during vibratory pile driving of 36-in and 
42-in steel piles and during all socketing/rock anchoring activities 
with locations as follows: PSO #1: Stationed at or near the site of 
pile driving; PSO #2: Stationed on Hoonah Island (northwest of the 
project site in Port Frederick Inlet) and positioned to be able to view 
south towards the project site; PSO #3: Stationed across Icy Strait 
north of the project site (on the mainland or the Porpoise Islands) and 
positioned to be able to view west into Icy Strait and southwest 
towards the project site; and PSO #4: Stationed on a vessel traveling a 
circuitous route through the Level B monitoring zone.
    In addition, PSOs will work in shifts lasting no longer than 4 
hours with at least a 1-hour break between shifts, and will not perform 
duties as a PSO for more than 12 hours in a 24-hour period (to reduce 
PSO fatigue).
    Monitoring of pile driving shall be conducted by qualified, NMFS-
approved PSOs, who shall have no other assigned tasks during monitoring 
periods. DPD shall adhere to the following conditions when selecting 
PSOs:
    [ssquf] Independent PSOs shall be used (i.e., not construction 
personnel);
    [ssquf] At least one PSO must have prior experience working as a 
marine mammal observer during construction activities;
    [ssquf] Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
    [ssquf] Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator shall be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction;
    [ssquf] DPD shall submit PSO CVs for approval by NMFS for all 
observers prior to monitoring.
    DPD shall ensure that the PSOs have the following additional 
qualifications:
    [ssquf] Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    [ssquf] Experience and ability to conduct field observations and 
collect data according to assigned protocols;
    [ssquf] Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    [ssquf] Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    [ssquf] Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior;
    [ssquf] Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary; and
    [ssquf] Sufficient training, orientation, or experience with the 
construction operations to provide for personal safety during 
observations.

Notification of Intent To Commence Construction

    DPD shall inform NMFS OPR and the NMFS Alaska Region Protected 
Resources Division one week prior to commencing construction 
activities.

Interim Monthly Reports

    During construction, DPD will submit brief, monthly reports to the 
NMFS Alaska Region Protected Resources Division that summarize PSO

[[Page 18519]]

observations and recorded takes. Monthly reporting will allow NMFS to 
track the amount of take (including extrapolated takes), to allow 
reinitiation of consultation in a timely manner, if necessary. The 
monthly reports will be submitted by email to a NMFS representative. 
The reporting period for each monthly PSO report will be the entire 
calendar month, and reports will be submitted by close of business on 
the fifth day of the month following the end of the reporting period 
(e.g., the monthly report covering September 1-30, 2019, would be 
submitted to the NMFS by close of business on October 5, 2019).

Final Report

    DPD shall submit a draft report to NMFS no later than 90 days 
following the end of construction activities or 60 days prior to the 
issuance of any subsequent IHA for the project. DPD shall provide a 
final report within 30 days following resolution of NMFS' comments on 
the draft report. Reports shall contain, at minimum, the following:
    [ssquf] Date and time that monitored activity begins and ends for 
each day conducted (monitoring period);
    [ssquf] Construction activities occurring during each daily 
observation period, including how many and what type of piles driven;
    [ssquf] Deviation from initial proposal in pile numbers, pile 
types, average driving times, etc.;
    [ssquf] Weather parameters in each monitoring period (e.g., wind 
speed, percent cloud cover, visibility);
    [ssquf] Water conditions in each monitoring period (e.g., sea 
state, tide state);
    [ssquf] For each marine mammal sighting:
    [cir] Species, numbers, and, if possible, sex and age class of 
marine mammals;
    [cir] Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
    [cir] Type of construction activity that was taking place at the 
time of sighting;
    [cir] Location and distance from pile driving activities to marine 
mammals and distance from the marine mammals to the observation point;
    [cir] If shutdown was implemented, behavioral reactions noted and 
if they occurred before or after shutdown.
    [cir] Estimated amount of time that the animals remained in the 
Level A or B Harassment Zone.
    [ssquf] Description of implementation of mitigation measures within 
each monitoring period (e.g., shutdown or delay);
    [ssquf] Other human activity in the area within each monitoring 
period;
    [ssquf] A summary of the following:
    [cir] Total number of individuals of each species detected within 
the Level B Harassment Zone, and estimated as taken if correction 
factor appropriate.
    [cir] Total number of individuals of each species detected within 
the Level A Harassment Zone and the average amount of time that they 
remained in that zone.
    [cir] Daily average number of individuals of each species 
(differentiated by month as appropriate) detected within the Level B 
Harassment Zone, and estimated as taken, if appropriate.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    As stated in the proposed mitigation section, shutdown zones that 
are larger than the Level A harassment zones will be implemented in the 
majority of construction days, which, in combination with the fact that 
the zones are so small to begin with, is expected avoid the likelihood 
of Level A harassment for six of the nine species. For the other three 
species (Steller sea lions, harbor seals, and harbor porpoises), a 
small amount of Level A harassment has been conservatively proposed 
because the Level A harassment zones are larger than the proposed 
shutdown zones. However, given the nature of the activities and sound 
source and the unlikelihood that animals would stay in the vicinity of 
the pile-driving for long, any PTS incurred would be expected to be of 
a low degree and unlikely to have any effects on individual fitness.
    Exposures to elevated sound levels produced during pile driving 
activities may cause behavioral responses by an animal, but they are 
expected to be mild and temporary. Effects on individuals that are 
taken by Level B harassment, on the basis of reports in the literature 
as well as monitoring from other similar activities, will likely be 
limited to reactions such as increased swimming speeds, increased 
surfacing time, or decreased foraging (if such activity were occurring) 
(e.g., Thorson and Reyff, 2006; Lerma, 2014). Most likely, individuals 
will simply move away from the sound source and be temporarily 
displaced from the areas of pile driving, although even this reaction 
has been observed primarily only in association with impact pile 
driving. These reactions and behavioral changes are expected to subside 
quickly when the exposures cease.
    To minimize noise during pile driving, DPC will use pile caps (pile 
softening material). Much of the noise generated during pile 
installation comes from contact between the pile being driven and the 
steel template used to hold the pile in place. The contractor will use 
high-density polyethylene (HDPE) or ultra-high-molecular-weight 
polyethylene (UHMW) softening material on all templates to eliminate 
steel on steel noise generation.
    During all impact driving, implementation of soft start procedures 
and monitoring of established shutdown zones will be required, 
significantly reducing the possibility of injury. Given sufficient 
notice through use of soft start (for impact driving), marine mammals 
are expected to move away from an irritating sound source prior to it 
becoming potentially injurious. In addition, PSOs will be stationed 
within the action area whenever pile driving/removal and socketing/rock 
anchoring activities are underway. Depending on the activity, DDP will 
employ the use of three to four PSOs to ensure all monitoring and 
shutdown zones are properly observed. Although the expansion of Berth 
facilities would have some permanent removal of habitat available to 
marine mammals, the area

[[Page 18520]]

lost would be small, approximately equal to the area of the cruise ship 
berth and associated pile placements. These impacts have been minimized 
by use of a floating, pile-supported design rather than a design 
requiring dredging or fill. The proposed design would not impede 
migration of marine mammals through the proposed action area. The small 
lightering facility nearer to the cannery would likely not impact any 
marine mammal habitat since its proposed location is in between two 
existing, heavily-traveled docks, and within an active marine 
commercial and tourist area. There are no known pinniped haulouts or 
other biologically important areas for marine mammals near the action 
area.
    In addition, impacts to marine mammal prey species are expected to 
be minor and temporary. Overall, the area impacted by the project is 
very small compared to the available habitat around Hoonah. The most 
likely impact to prey will be temporary behavioral avoidance of the 
immediate area. During pile driving/removal and socketing/rock 
anchoring activities, it is expected that fish and marine mammals would 
temporarily move to nearby locations and return to the area following 
cessation of in-water construction activities. Therefore, indirect 
effects on marine mammal prey during the construction are not expected 
to be substantial.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
    [ssquf] No mortality is anticipated or authorized;
    [ssquf] Minimal impacts to marine mammal habitat are expected;
    [ssquf] The action area is located and within an active marine 
commercial and tourist area;
    [ssquf] There are no rookeries, or other known areas or features of 
special significance for foraging or reproduction in the project area;
    [ssquf] Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior; and
    [ssquf] The required mitigation measures (i.e. shutdown zones and 
pile caps) are expected to be effective in reducing the effects of the 
specified activity.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.
    Six of the nine marine mammal stocks proposed for take is less than 
five percent of the stock abundance. For Alaska resident, northern 
resident and transient killer whales, the number of proposed instances 
of take as compared to the stock abundance are 19.9 percent, 19.9, and 
20.2 percent, respectively. However, since three stocks of killer 
whales could occur in the action area, the 570 total killer whale takes 
are likely split among the three stocks. Nonetheless, since NMFS does 
not have a good way to predict exactly how take will be split, NMFS 
looked at the most conservative scenario, which is that all 570 takes 
could potentially be distributed to each of the three stocks. This is a 
highly unlikely scenario to occur and the percentages of each stock 
taken are predicted to be significantly lower than values presented in 
Table 9 for killer whales. Further, these percentages do not take into 
consideration that some number of these take instances are likely 
repeat takes incurred by the same individuals, thereby lowering the 
number of individuals.
    There are no official stock abundances for harbor porpoise and 
minke whales; however, as discussed in greater detail in the 
``Description of Marine Mammals in the Area of Specified Activities,'' 
we believe for the abundance information that is available, the 
estimated takes are likely small percentages of the stock abundance. 
For harbor porpoise, the abundance for the Southeast Alaska stock is 
likely more represented by the aerial surveys that were conducted as 
these surveys had better coverage and were corrected for observer bias. 
Based on this data, the estimated take could potentially be 
approximately 17 percent of the stock abundance. However, this is 
unlikely and the percentage of the stock taken is likely lower as the 
proposed take estimates are conservative and the project occurs in a 
small footprint compared to the available habitat in Southeast Alaska. 
For minke whales, in the northern part of their range they are believed 
to be migratory and so few minke whales have been seen during three 
offshore Gulf of Alaska surveys that a population estimate could not be 
determined. With only nine proposed takes for this species, the 
percentage of take in relation to the stock abundance is likely to be 
very small.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In September 2018, DPD contacted the Indigenous People's Council 
for Marine Mammals (IPCoMM), the Alaska Sea Otter and Steller Sea Lion 
Commission, and the Hoonah Indian Association (HIA) to determine 
potential project impacts on local subsistence activities. No comments 
were received from IPCoMM or the Alaska Sea Otter and Steller Sea Lion 
Commission. On October 23, 2018, a conference call between 
representatives from DPD, Turnagain Marine Construction, SolsticeAK, 
and the HIA were held to discuss tribal concerns regarding subsistence 
impacts. The tribe confirmed that Steller sea lions and harbor seals 
are harvested in and around the project area. The HIA referenced the 
2012 subsistence technical paper by Wolf et al. (2013) as the most 
recent information available on marine mammal harvesting in Hoonah and 
agreed that the proposed construction activities are unlikely to have 
significant impacts to marine mammals as they are used in subsistence 
applications. Information on the timing of the IHA issuance was 
provided by DPD via email to the tribe on October 23, 2018. There have 
been no further comments on this project.
    Therefore, we believe there are no relevant subsistence uses of the 
affected marine mammal stocks or species implicated by this action. 
NMFS has preliminarily determined that the total taking of affected 
species or stocks would not have an unmitigable adverse impact on the 
availability of such

[[Page 18521]]

species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the Alaska Regional Office 
(AKRO) whenever we propose to authorize take for endangered or 
threatened species.
    NMFS is proposing to authorize take of Mexico DPS humpback whales, 
which are listed and Western DPS Steller sea lions under the ESA. The 
Permit and Conservation Division has requested initiation of Section 7 
consultation with the Alaska Regional Office for the issuance of this 
IHA. NMFS will conclude the ESA consultation prior to reaching a 
determination regarding the proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to DPD's for conducting for the proposed pile driving and 
removal activities for construction of the Hoonah Berth II cruise ship 
terminal and lightering float, Icy Strait, Hoonah Alaska for one year, 
beginning June 2019, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. A draft of the 
proposed IHA can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed pile 
driving and removal activities for construction of the Hoonah Berth II 
cruise ship terminal and lightering float. We also request comment on 
the potential for renewal of this proposed IHA as described in the 
paragraph below. Please include with your comments any supporting data 
or literature citations to help inform our final decision on the 
request for MMPA authorization.
    On a case-by-case basis, NMFS may issue a one-year IHA renewal with 
an expedited public comment period (15 days) when (1) another year of 
identical or nearly identical activities as described in the Specified 
Activities section is planned or (2) the activities would not be 
completed by the time the IHA expires and a second IHA would allow for 
completion of the activities beyond that described in the Dates and 
Duration section, provided all of the following conditions are met:
    [ssquf] A request for renewal is received no later than 60 days 
prior to expiration of the current IHA.
    [ssquf] The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
proposed Renewal are identical to the activities analyzed under the 
initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal); and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    [ssquf] Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: April 26, 2019.
Catherine G. Marzin,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2019-08848 Filed 4-30-19; 8:45 am]
BILLING CODE 3510-22-P